We don't have synonyms for tee ball yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are tea ball, tee-ball and teeball.
(n) :
Alternative spelling of T-ball. [(US, uncountable) A form of baseball, played by young children, in which the batter hits a ball placed on a tee rather than being thrown by a pitcher.]
(n) :
Alternative spelling of T-ball. [(US, uncountable) A form of baseball, played by young children, in which the batter hits a ball placed on a tee rather than being thrown by a pitcher.]