adj. shirt·i·er, shirt·i·est
Ill-tempered; angry: "He saw how shirty she was about it" (P.G. Wodehouse).
[Probably from to get someone's shirt out, to annoy, or to keep one's shirt on, to keep from being annoyed.]
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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.