- heel-tap (n.)
[heel-tap 词源字典]
- also heeltap, 1680s, "one of the bits of leather that are stacked up to make a shoe heel" (see heel (n.1)); meaning "bit of liquor left in a glass or bottle" first recorded 1780s; the exact connection is uncertain unless it be "the last or final part."[heel-tap etymology, heel-tap origin, 英语词源]