noun
plural shirts
[count] :a piece of clothing for the upper body that has sleeves and usually a collar and buttons down the front - see also nightshirt, polo shirt, stuffed shirt, sweatshirt, t-shirt, undershirt
keep your shirt on
informal - used to tell someone to calm down or be more patient
lose your shirt
chiefly US informal :to lose a lot of money because of a bad bet or investment
put your shirt on
chiefly Brit informal :to bet a lot of money on (someone or something)
the shirt off your back
informal
People who would give you the shirt off their back would do anything to help you.
US