Origin and history of tig

children's game in which one player ("it") chases the others and attempts to touch them, by 1738 (in a reference to "Queen Mary's reign"), perhaps a variation of Scottish tig "touch, tap" (1721, also attested as the name of the game), which is probably an alteration of Middle English tek, tik "touch, tap" (see tick (n.2)).

The baseball sense of "act of putting out an opposing player by touching him with the ball" is by 1912. It is not an acronym; it does not stand for anything.

early 14c., "light touch or tap" (now obsolete or dialectal), probably from tick (v.), which is attested earlier. Compare Dutch tik, Middle High German zic; all are perhaps ultimately echoic.

The meaning "recurring clicking sound made by the mechanism of a clock" is probably attested by 1540s; hence "time between two ticks of a clock or watch" (1879); also compare tick-tock.

As "dot or slight mark made over a letter, or beside a name or passage" it is recorded by 1844; ticks were another name for "quotation marks;" hence perhaps tick off. It also was another name of the game of tag (n.2) or tig (Drayton, "Poly-olbion"). The meaning "small spot on the coat of an animal" (ticked, of dogs, is from 1680s) perhaps is from resemblance to the parasite and belongs to tick (n.1).