snot running down his cheek

昨日のラグビー早明戦は、前週の早慶戦と違って、素晴らしい試合でした。点の取り合いで、敗れた明治もロストタイムのギリギリまで逆転を狙う良い試合で満足しました。
さて、Natsuo Kirinoの "OUT" を読んでいます。

The girl's dyed brown hair fell straight down almost to her waist, and tugging at the ends of it was a small boy who was staring up at Yoshie. This must be the child she'd heard rumors about a couple of years ago, her first grandchild. He looked exactly like his useless father, and none too cute at that. He was thin and pale, with a line of snot running down his cheek. The boy's dad was a loser who had hung around the neighborhood, never able to hold down a regular job; and now his child was watching her with a knowing sort of look, as if he'd guessed what she was thinking.

"snot" は知らない単語ですが、"a line of snot running down his cheek" とあるので鼻水と分かりますね。一応辞書の説明を見ます。

・Collins Dictionary: Snot is the substance that is produced inside your nose. [informal, rude]: She was crying now and clear snot ran in channels from her nose.
・Vocabulary.com: Snot is the discharge that comes from your nose when you have a bad cold. You'll want to carry tissues or a handkerchief with you when you're sneezing, to keep the snot contained.
There are two meanings of the noun snot: the first, mucus, can be unpleasant. The second meaning, an irritatingly arrogant person, is also unpleasant. If a little kid acts like a snot, his babysitter is definitely not going to let him stay up past his bedtime. If you're a snot to your best friend, she might not speak to you the next day. Snot comes from the Old English word gesnot, or "nasal mucus," from a Germanic root.