a piece of wood with a handle, made in various shapes and sizes, and used for hitting the ball in games such as baseball, cricket and table tennis 球棒；球拍；球板 
a baseball/cricket bat 棒球球棒；板球球板
Oxford Collocations Dictionaryadjective- baseball
- cricket
- table-tennis
- …
- grip
- hold
- carry
- …
an animal like a mouse with wings that flies and feeds at night (= it is nocturnal). There are many types of bat. 蝙蝠 
Oxford Collocations Dictionaryadjective- fruit
- vampire
- etc.
- …
- flutter
- fly
- hang
- …
Word Originnoun sense 1 late Old English batt ‘club, stick, staff’, perhaps partly from Old French batte, from battre ‘to strike’. noun sense 2 late 16th cent.: alteration, perhaps by association with medieval Latin batta, blacta, of Middle English bakke, of Scandinavian origin.
Idioms
at bat
(in baseball 棒球 trying to hit the ball with a bat 用球板击球，用球棒击球（尤指板球或棒球运动） It's his first time at bat in the major leagues. 这是他第一次在大联盟打球。
(as) blind as a bat
- (humorous)
not able to see well 视力不佳 She’s as blind as a bat without her glasses. 她不戴眼镜就像蝙蝠一样瞎。
More Like This Similes in idiomsSimiles in idioms- (as) bald as a coot
- (as) blind as a bat
- (as) bright as a button
- (as) bold as brass
- as busy as a bee
- as clean as a whistle
- (as) dead as a/the dodo
- (as) deaf as a post
- (as) dull as ditchwater
- (as) fit as a fiddle
- as flat as a pancake
- (as) good as gold
- (as) mad as a hatter/a March hare
- (as) miserable/ugly as sin
- as old as the hills
- (as) pleased/proud as Punch
- as pretty as a picture
- (as) regular as clockwork
- (as) quick as a flash
- (as) safe as houses
- (as) sound as a bell
- (as) steady as a rock
- (as) thick as two short planks
- (as) tough as old boots
like a bat out of hell
- (old-fashioned, informal)
very fast 疾速地；迅速地 She was driving like a bat out of hell. 她开得飞快。
off your own bat
- (British English, informal)
if you do something off your own bat, it is your own idea and you do it without help or support from anyone else 自觉地；主动地 She made the suggestions entirely off her own bat. 她完全凭直觉提出了这些建议。
right off the bat