bat / batt are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
bat: (noun) nocturnal mouselike mammal with forelimbs modified to form membranous wings and anatomical adaptations for echolocation by which they navigate. (noun) (baseball) a turn trying to get a hit. (noun) a club used for hitting a ball in various games. (verb) strike with, or as if with a baseball bat. (verb) wink briefly. (verb) have a turn at bat. (verb) use a bat.
batt: NA
bat: b·AE·t
batt: b·AE·t
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)