under his belt

Grishamの短編小説集Ford Countyの中のQuiet Havenを読んでいます。
Because of the popularity of these lawsuits, and the sheer number of vultures circling nursing homes, I have learned that one must move with haste. My lawyer is an old friend named Dexter Ridley, from Tupelo, a man I turn to on occasion. Dex is about fifty, with a couple of wives and lives under his belt, and he made the decision a few years ago that he could not survive in the business by drawing up deeds and filing no-fault divorces.
慣用句らしき "lives under his belt" の意味が分かりません。 "under his belt" を辞書で調べます。
・Oxford English Dictionary: Safely or satisfactorily achieved, experienced, or acquired: I want to get more experience under my belt.: he now has almost a year as president under his belt
・Merriam-Webster's Online Dictionary: as an achievement or as part of one's experience: an actor who has several films under his belt: He finally has a full year of experience under his belt.
なるほど、今の私が小さな専門商社でパートとして働いている状況の説明に使えそうです。
I work as a part-timer at a small trading company near Akahabara under my belt.