Definition from Wiktionary, the free dictionary
Alternative forms 
The "c" in tic, tac, or both may be replaced with a "ck" or with a "t":
- tick-tack-toe; tick-tat-toe; tit-tat-toe, etc.
The phrase, or one of the above variations, may be presented without hyphens:
- tic tac toe; tick tat toe; tit tat toe, etc.
- (games) A game in which two players take turns putting circles and crosses on a 3x3 grid and try to get three of the same symbols in a line
- noughts and crosses or naughts and crosses (mostly British)
- X's and O's (English - Ireland)
- X-e O-zees (Northern Ireland)
- Boxin' OXen (Southern Ireland)
- Twiddles & Bears (Norway)