1. A garment for the upper part of the body, typically having a collar, sleeves, and a front opening.
2. An undershirt.
3. A nightshirt.
keep (one's) shirt on Slang
To remain calm or patient: The plane doesn't land for another hour, so keep your shirt on.
lose (one's) shirt Slang
To lose everything one has or owns.
the shirt off (one's) back Slang
The maximum one is able to give or lose: The only thing those swindlers didn't take was the shirt off my back.
[Middle English shirte, from Old English scyrte, short garment; see sker-1 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.