n. & v.
n. 1 a device by which a flow of liquid or gas from a pipe or vessel can be controlled. 2 an act of tapping a telephone etc. 3 Brit. a taproom. 4 an instrument for cutting the thread of a female screw.
v.tr. (tapped, tapping) 1 a provide (a cask) with a tap. b let out (a liquid) by means of, or as if by means of, a tap. 2 draw sap from (a tree) by cutting into it. 3 a obtain information or supplies or resources from. b establish communication or trade with. 4 connect a listening device to (a telephone or telegraph line etc.) to listen to a call or transmission. 5 cut a female screw-thread in. on tap 1 ready to be drawn off by tap. 2 colloq. ready for immediate use; freely available. tap root a tapering root growing vertically downwards. tap water water from a piped supply. tapless adj. tappable adj.
[ OE tppian (v.), tppa (n.) f. Gmc ]