- 1男性三角內褲（前面開口呈倒 Y 字形的那種）；英式用法，帶點好笑、老派的味道。買東西時說 briefs 比較中性通用。
Y-fronts are men's with a seam at the front shaped like an upside-down Y — two lines coming down to meet a vertical opening in the middle. The name is British, from a brand, and it has become the ordinary word there for that close-fitting style, what Americans would call briefs. The word is plural, like trousers and jeans: you say a pair of Y-fronts, my Y-fronts are in the wash — never "a Y-front". This is a British word, informal and slightly comic. In Britain, Y-fronts carry a picture with them: the underwear of older men, of dads and , , the opposite of boxer shorts. So it turns up in jokes and teasing far more often than in shops. If you simply want to buy this kind of underwear, ask for briefs — that is the neutral word and it works everywhere in English. Spelling varies: Y-fronts, Y-Fronts, sometimes y-fronts.
組成Y（前面接縫倒過來的 Y 形狀）+ fronts（前面那一片）。原是英國的商標名，後來變成一般說法。
原始詞典資料1 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
Y-frontsnoun
- 1
informalBriefs that have a fly as part of an inverted Y formed by the seams.
- Setting a spatted foot on the bench that ran down the middle of the changing-room with elegant distain, Adrian began to flip through a pile of Y-fronts and rugger shorts with his cane.
- I did the latter, so in writing this I have put it on record that I am one of the few men who has spent Christmas Eve running across a Kentish marsh in his Y-fronts with two horses trotting after him in close company.
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。