tap

knock, tap, rap, pat

这些动词均有“敲、击”之意。
knock: 指用拳头或其它器械猛敲或猛打；也指用手轻敲某物。
tap: 多指慢慢地、连续地轻击或轻拍。
rap: 指用手指或木棒等快速地轻敲或急拍。
pat: 指用手轻拍以示同情、赞同或爱抚。

名词 tap:

1. the sound made by a gentle blow
   同义词：pat, rap
2. a faucet for drawing water from a pipe or cask
   同义词：water faucet, water tap, hydrant
3. a gentle blow
   同义词：rap, strike
4. a small metal plate that attaches to the toe or heel of a shoe (as in tap dancing)
5. a tool for cutting female (internal) screw threads
6. a plug for a bunghole in a cask
   同义词：spigot
7. the act of tapping a telephone or telegraph line to get information
   同义词：wiretap
8. a light touch or stroke
   同义词：pat, dab

动词 tap:

1. cut a female screw thread with a tap
2. draw from or dip into to get something
3. strike lightly
   同义词：tip
4. draw from; make good use of
   同义词：exploit
5. tap a telephone or telegraph wire to get information
   同义词：wiretap, intercept, bug
6. furnish with a tap or spout, so as to be able to draw liquid from it
7. make light, repeated taps on a surface
   同义词：rap, knock, pink
8. walk with a tapping sound
9. dance and make rhythmic clicking sounds by means of metal plates nailed to the sole of the dance shoes
   同义词：tapdance
10. draw (liquor) from a tap
11. pierce in order to draw a liquid from
12. make a solicitation or entreaty for something; request urgently or persistently
    同义词：solicit, beg

1. That girl tapped her fingers on the desk impatiently.
   那个女孩不耐烦地用手指轻扣桌面。
2. He cleaned his hands in the cold water from the tap.
   他用自来水龙头流出的凉水把手洗干净。
3. My phone is being tapped.
   有人在窃听我的电话。