gag reflex

コロナ感染の勢いは収まるどころか広がる一方ですね。　コロナ感染を取り上げたReader's Digestの記事 '20 Pains To Never Ignore' からの引用です。
Among the most disturbing symptoms was his lack of taste and smell. "I couldn't differentiate between cake and pizza. The texture was the same, and there was absolutely no taste. I had to force myself to eat because my gag reflex was so strong. I didn't attribute this to COVID-19 originally, but now I see that it's one of the defining symptoms," Stillman says.
いまや世界中に蔓延しているCOVID-19に罹った人の症状の例ですが、"gag reflex" が分かりません。 "reflex" とあるので、体のどこかの反射動作/神経の作用を指すようですが、辞書を見ます。
・Vocabulary.com: normal reflex consisting of retching; may be produced by touching the soft palate in the back of the mouth

・Wiktionary: A reflex contraction of the back of the throat, evoked by touching the soft palate.

・Wikipedia: The pharyngeal reflex, gag reflex, or laryngeal spasm, is a reflex contraction of the back of the throat, evoked by touching the roof of the mouth, the back of the tongue,
舌ブラシなどで舌の奥に触れるとオエッとなるやつですね。

teething fever

Banana Yoshimotoの "Kitchen" を読んでいます。
With all that activity, my fever went up. It makes sense, I thought; it simply follows that if one goes running around town in the condition I was in, delirious, this would be the result.
My mother laughed and asked me if it might not be like a teething fever. Weakly, I laughed back.
"teething fever" だと熱が出るほどの歯の痛みに思えますが、どうでしょうか？
・Oxford English Dictionary: The process of growing or cutting milk teeth.: Remedies specifically for teething are available from pharmacies, supermarkets and health food stores.

・Collins Dictionary: When babies are teething, their teeth are starting to appear through their gums, often causing them pain.: Camomile has long been used as a remedy for teething babies.

・Cambridge English Dictionary: If a baby or small child is teething, their first teeth are growing, usually causing pain: My sister was up most of the night with her baby who's teething.
"teething" は赤ちゃんの歯が生えることを意味しているのですね。

take-no-prisoners

Banana Yoshimotoの "Kitchen" を読んでいます。
I was amazed when I saw her play. Hitoshi seemed surprised, too. Hiiragi said with pride, "See what I mean? Incredible, isn't she?"
She played a take-no-prisoners game of tennis, propelled by the full force of her intensity and powers of concentration.
"take-no-prisoners" 語源が知りたくなる表現ですね。とりあえず意味を調べます。
・Merriam-Webster's Online Dictionary: having a fierce, relentless, or merciless character: take-no-prisoners politics
・American Heritage Dictionary: Extremely ardent or aggressive: "a take-no-prisoners arrogance that alienates others"

・Dictionary.com: wholeheartedly aggressive; zealous; gung-ho: a businessman with a take-no-prisoners attitude toward dealmaking.
語源はUrban Dictionary次の説明がありました。
Derived from a phrase used in wars. When a captain shouts "Take no prisoners!" He means, kill all of those that are captured. Back in the late 19th century, when wars were won either they took their enemies as slaves back to their own country or they kill them.
皆殺しですか、恐ろしい。

get it over with

Banana Yoshimotoの "Kitchen" を読んでいます。
Everyone out on the streets was coming and going, looking happy, the light shining through their hair. Everything was breathing, increasingly sparkling, swathed in the gentle sunlight. The pretty scene was brimming with life, but my soul was pining for the desolate streets of winter and for that river at dawn. I wished my heart would break and get it over with.
"get over" で打ち勝つとか克服する意味がありますが、"get it over with" はこれで慣用句として覚えた方が良さそうです。辞書に説明があるか見ます。
・Wiktionary: An exhortation to do something quickly (typically because it is unpleasant).: I know you have to draw blood, so go ahead, get it over with!

・Farlex Dictionary of Idioms: (idiomatic) To do or finish, especially said of something unpleasant.: He didn’t want to go to the doctor for his shots, but he decided it would be better just to get it over with.
"get over" は困難に対峙していますが、"get it over with" は 'typically because it is unpleasant' な事に対して使われることが多いのですね。

toasty

Banana Yoshimotoの "Kitchen" を読んでいます。
The little second-floor tea shop was quiet and cheerful. Surrounded by white walls, the place was warm and toasty.
朝食はいつもトーストのオープンサンドを食べているので "toasty" からは食べ物のトーストしか連想できませんが、何か良い意味を持つ形容詞のようです。辞書を見ます。
・Oxford English Dictionary: Comfortably warm.: Nothing beats the toasty comfort of a flickering blaze in the hearth while Old Man Winter rages just beyond the walls.

・Collins Dictionary: If something is toasty, it is comfortably warm.: [informal] The room was toasty. The sun was streaming through the windows.

・Cambridge English Dictionary: comfortably and pleasantly warm: My feet feel so warm and toasty in the new slippers.
分かりましたが、今は冬ではないので実感が湧かないですね。.

Wash Your Hands

これもReader's Digest 6月号の 'Laughter is Good Medicine!' からの引用です。
Due to local cases of #COVID-19, the Puyallup (Washington) Police Department is asking all criminal activities and nefarious behavior to cease. We appreciate your cooperation in halting crime & thank you the criminals in advance. We will let you know when you can resume your normal behavior. Until then #washyourhands.
冗談でしょう？　三蜜と違って犯罪からは永久に手を洗って欲しいですね。

Introverts

コロナ対策には３密を避けることが重要とされていますが、昔からそれを守っている人が米国にもいます。
Reader's Digest 6月号の 'Laughter is Good Medicine!' から引用します。
CDC: To prevent coronavirus, stay home, avoid physical contact, and don't go into large crowds.
Introverts: I've been preparing for this moment my entire life.

home ec

Banana Yoshimotoの "Kitchen" を読んでいます。
Dividing ingredients into bowls, bringing giant vats of water to a boil, measuring--doing routine work until three o'clock suited me fine. This sunny, large-windowed room, those big tables lined up in front of the ovens, the broilers and burners, reminded me of the home-ec rooms at school.
"home-ec" は授業の種類の様ですが何でしょう？
・Oxford English Dictionary: short for home economics; Cooking and other aspects of household management, especially as taught at school.: I had all the usual classes, plus physical education and home economics.

・Collins Dictionary: Home economics is a school subject dealing with how to run a house well and efficiently.: Maybe that's why I took home economics at school.

・Cambridge English Dictionary: at school, the study of cooking, sewing, and subjects relating to the management of a home: They also prefer religious education, home economics and sports studies.

three sheets to the wind

Banana Yoshimotoの "Kitchen" を読んでいます。
Yuichi, uncharacteristically, was very drunk. Just as I was thinking that it was off--I didn't see him have that much at dinner--I noticed, with a start, an empty bottle on the floor. Apparently he had been at it while I was cooking; no wonder he was three sheets to the wind. I asked him, amazed, "Youich, did you drink this whole bottle before dinner?"
この "three sheets to the wind" も慣用句ですね。
・Farlex Dictionary of Idioms: slang Extremely drunk, especially to the point of being uncoordinated or out of control. Most likely derived from nautical terminology, in which a "sheet" is the rope that controls the sails of a tall ship; if several sheets are loose or mishandled, the boat's movement becomes unsteady and difficult to control, like that of a drunk person.: On his 21st birthday, Jeff's friends took him to every bar in town until he was three sheets to the wind.

・Collins COBUILD Idioms Dictionary: If someone is three sheets to the wind, they are drunk.: He's probably three sheets to the wind down at Toby's,

・Wiktionary: (idiomatic) Drunk.: That late in the evening, he was three sheets to the wind and had long since stopped making sense.
これは語源が分かりました。

under my belt

Banana Yoshimotoの "Kitchen" を読み始めました。
吉本ばななの小説を読むのは初めてです。名前から吉本興業のタレントから小説家になった人と思っていましたが、吉本興業とは全く関係がない方でした。
Getting the job I have now, as an assistant to a cooking teacher, was incredible. She not only teaches cooking classes, but also gets a lot of important television and magazine work, and she is actually rather famous. An amazing number of candidates apparently tested for the job. Why was it that I--a novice with only one summer of study under my belt--got hired?
慣用句らしい "under my belt" の意味を辞書で調べます。
・Oxford English Dictionary: Safely or satisfactorily achieved, experienced, or acquired.: He now has almost a year as president under his belt.

・Collins Dictionary: as part of one's experience: he had a linguistics degree under his belt

・Wiktionary: Already done; within one's experience; practiced. quotations: He got off to a shaky start, but with a few months of experience under his belt, he kept up handily with the veteran employees.
由来が気になる表現ですが、語源は分かりませんでした。