tap

Etymology 1

From Middle English tappe, from Old English tæppa, from Proto-Germanic *tappô. The verb is from Middle English tappen, from Old English tæppian, from Proto-Germanic *tappōną, from the noun.

noun

1. A tapering cylindrical pin or peg used to stop the vent in a cask.
2. A device used to dispense liquids.
   We don't have bottled water; you'll have to get it from the tap.
3. Liquor drawn through a tap; hence, a certain kind or quality of liquor.
   a liquor of the same tap
4. A place where liquor is drawn for drinking.
5. (mechanics) A device used to cut an internal screw thread. (External screw threads are cut with a die.)
   We drilled a hole and then cut the threads with the proper tap to match the valve's thread.
6. A connection made to an electrical or fluid conductor without breaking it.
   The system was barely keeping pressure due to all of the ill-advised taps along its length.
7. An interception of communication by authority.
8. A device used to listen in secretly on telephone calls.
9. (medicine, informal) A procedure that removes fluid from a body cavity.
   abdominal tap
   pleural tap
   spinal tap
10. (finance) The situation where a borrowing government authority issues bonds over a period of time, usually at a fixed price, with volumes sold on a particular day dependent on market conditions.
    tap issue; a bond tap

verb

1. To furnish with taps.
   If we tap the maple trees, we can get maple syrup!
2. To draw off liquid from a vessel.
   He tapped a new barrel of beer.
3. To deplete, especially of a liquid via a tap; to tap out.
4. To exploit.
   Businesses are trying to tap the youth market.
5. To place a listening or recording device on a telephone or wired connection.
   They can't tap the phone without a warrant.
   Minister: There is one thing: how did you know whose telephone to tap? / Lebel: I didn't, so I tapped all of them. 1973, Frederick Forsyth (book), Kenneth Ross (screenplay), Chacal (motion picture)
6. To intercept a communication without authority.
   He was known to tap cable television.
7. (mechanical) To cut an internal screw thread.
   Tap an M3 thread all the way through the hole.
8. (card games, board games) To turn or flip a card or playing piece to remind players that it has already been used that turn (by analogy to "tapping," in the sense of drawing on to the point of temporary exhaustion, the resources or abilities represented by the card).
   I think there's an expression in poker. I'll tap you, Mr. Maverick. 1957, “According to Hoyle”, in Maverick (televison production), spoken by Samantha Crawford (Diane Brewster)
9. (informal) To cadge, borrow or beg.
   I tried to tap a cigarette off him, but he wouldn't give me one.
10. (medicine, informal) To drain off fluid by paracentesis.
11. To advance someone for a post or job, or for membership of a club.
    Trump interviewed Mueller for FBI job day before he was tapped for special counsel.
12. (slang) To arrest.

Etymology 2

From Middle English tappen, teppen, from Old French tapper, taper (“to tap”), of Germanic origin, from Frankish *tappōn, *dabbōn (“to strike”) or from Middle Low German tappen, tapen ("to tap, rap, strike"); both ultimately from Proto-Germanic *dab- (“to strike”), from Proto-Indo-European *dʰAbʰ- (“to beat, strike, stun, be speechless”). Related to German tappen (“to grope, fumble”), Icelandic tappa, tapsa, tæpta (“to tap”). Related to dab.

verb

1. To strike lightly.
   She tapped him on the shoulder to get his attention.
2. To touch one's finger, foot, or other body parts on a surface (usually) repeatedly.
   He was so nervous he began to tap his fingers on the table.
   She tapped her companion on the back to indicate that she was ready to go.
   Lydia tapped Jim on the shoulder to get his attention.
3. To make a sharp noise.
   The tree, swaying in the breeze, began to tap on the window pane.
4. (graphical user interface) To operate an electronic device (e.g. a mobile phone) by tapping a specific place on its (capacitive or other) touch screen.
   Coordinate term: click
   Tap the Save Image button to save the picture in your iPod touch or iPhone photo library (in the Saved Images album) or tap Cancel to cancel. 2010, Tony Bove, iPod & iTunes For Dummies, John Wiley & Sons, page 302
5. To designate for some duty or for membership, as in 'a tap on the shoulder'.
6. (slang, vulgar, transitive) To have sexual intercourse with.
   I would tap that hot girl over there.
   I'd tap that.
   What we're entitled to is a house in the Hamptons. Maybe a perscription drug problem. But happiness does not seem to be on the menu so smoke up and seal the deal with Blair because you're also entitled to tap that ass. 2007, “Pilot”, in Gossip Girl (television production), spoken by Chuck Bass (Ed Westwick)
7. (combat sports) To submit to an opponent by tapping one's hand repeatedly.
8. (combat sports, transitive) To force (an opponent) to submit.
   Hard to believe Kimo [Leopoldo] used a triangle choke to tap [Kazushi] Sak[uraba], but 4 years can make a difference. 2000-10-14, "K®Æz¥ k ° †€°" (username), “Kimo Tapped Sakuraba”, in alt.ufc (Usenet)
   Just started bjj [=Brazilian Jiu-Jitsu] couple of months ago and i finally tapped someone!!! WOOOHOO! The guy i tapped has been traiing a few more months than me, outweighs me by at least 30 pounds, and is in great shape from the army. 2003-04-02, "Eddie" (username), “I Tapped Somebody!”, in rec.martial-arts (Usenet)
   [Genki] Sudo weighed 1/4 of what Butterbean [=Eric Esch] weighs and he still tapped Butterbean. 2004-04-07, "Araxen" (username), “Re: UFC vs. Boxing”, in rec.sport.boxing (Usenet)
9. To put a new sole or heel on.
   to tap shoes

noun

1. A gentle or slight blow; a light rap; a pat.
   When Steve felt a tap on his shoulder, he turned around.
2. (dance) Ellipsis of tap dance.
3. (computing, graphical user interface) The act of touching a touch screen.
   Coordinate term: click
4. A piece of leather fastened upon the bottom of a boot or shoe in repairing or renewing the sole or heel.
5. (military) A signal, by drum or trumpet, for extinguishing all lights in soldiers' quarters and retiring to bed; usually given about a quarter of an hour after tattoo.
6. (phonetics) A consonant sound made by a single muscle contraction, such as the sound [ɾ] in the standard American English pronunciation of body.
7. Short for tap of work.

Etymology 3

From Persian or Urdu تب (tab, “malarial fever”), ultimately from Sanskrit ताप (tāpa, “fever; heat; pain, torment”).

noun

1. An Indian malarial fever.