Oxford Advanced American Dictionary

Definition of shirt noun from the Oxford Advanced Learner's Dictionary

Oxford3000

shirt

noun
shirt pronunciation English ʃɜːt shirt pronunciation American ʃɜːrt
 
a piece of clothing (usually for men), worn on the upper part of the body, made of light cloth, with sleeves and usually with a collar and buttons down the front
to wear a shirt and tiea short-sleeved shirta football shirt see also nightshirt, polo shirt, stuffed shirt, sweatshirt, T-shirt
Idioms

keep your shirt on

(informal) used to tell somebody not to get angryKeep your shirt on! It was only a joke.

put your shirt on somebody/something

(British English, informal) to bet all your money on somebody/somethingIt's a good horse, but I wouldn't put my shirt on it.

the shirt off somebody's back

anything that somebody has, including the things they really need themselves, that somebody else takes from them or they are willing to give
He was the type of person who would give you the shirt off his back.