the shirt off someone's back

shirt | American Dictionary

shirt
noun[ C ]
us/ʃɜrt/
a piece of clothing worn on the upper part of the body, made of cloth and often having a collar and buttons at the front:
a short-sleeved/long-sleeved shirt
Her shirt was untucked.

Examples of shirt

shirt
He gradually expanded his business, and obtained his own kiosk from which he sold shirts.
She brings illustrated and other papers, books of stories, little comforts in the way of eating and drinking, shirts, gowns, handkerchiefs, c.
A great 'sail' of drying shirts rises slowly over their heads.
The shirts can be ruffled or button-down, worn with vests or abandoned altogether for soft but sleeveless sweater tops.
You see us taking our shirts off?
The expression of pity and the wry references to the men's work and discomfort (wet shirts) divert attention from the harsh reality of the repeated flogging of the dogs.
An important contributing factor to the lack of hierarchy was that the team wore identical uniforms irrespective of profession or role within the team (red polo shirts and navy trousers).
Of course, not all have reached this 'pinnacle' of physical development; there are many whose shirts stay on (probably around fifty per cent) and whose clothes are less revealing.
On reception prisoners are given two clean shirts, two clean pairs of socks and one clean handkerchief.
From the
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