waistcoat

(US also vest) n close-fitting sleeveless garment, buttoned down the front, usu worn under a jacket or coat and often forming part of a man's suit （西服的）背心.

wages, waggish, waggishly, waggishness, waggle, waggon, wagon, wagon (Brit also waggon), wagon-lit, wagoner (Brit also waggoner), wagtail, waif, wail, wainscot, wainscoted, wainscoting, waist, waist-deep, waist-high, waistband, waisted, waistline, wait, wait at table, wait for, wait on, wait up for, waiter, waiting room, waiting-list, waiting-room, waitress, waive, waiver, wake, wake up, wake up to, wakeful, wakefully, wakefulness,