(countable, uncountable) A diminutive of the female given name Katherine, variant of Katie.
Come along, you’re the first of the Katies. Now Katy was a tom-boy, […] Have you got a copy of the script? 1961, Rosemary Weir, “Television Centre”, in Tania Takes the Stage, London: Hutchinson & Co. (Publishers) Ltd., →OCLC, pages 88–89:
The very first thing, however, Ernest annoyed me by calling me Katherine, though he knows I hate that name, and want to be called Katy as if I were a lovable person, as I certainly am (sometimes). 1876 Elizabeth Prentiss: Stepping Heavenward, and Aunt Jane's Hero. Ward, Lock&Tyler 1876. page 87
Katy Carr serves her sentence with pain and her character changes as a result – or so the author implies; but the two Katys, the hoyden and the high-principled young lady, hardly seem to be the same girl. 1975, Margery Fisher, “Katy Carr”, in Who’s Who in Children’s Books: A Treasury of the Familiar Characters of Childhood, New York, N.Y.: Holt, Rinehart and Winston, →ISBN, page 166, column 1:
(countable, uncountable, with the) The Missouri–Kansas–Texas (MKT) Railroad.
When the Katy came through, the town’s entire economy and culture changed.
(countable, uncountable) A locale in the United States. ▸ A city at the tripoint of Harris County, Fort Bend County and Waller County, Texas; named for the MKT railroad.
(countable, uncountable) A locale in the United States. ▸ An unincorporated community in Missouri.
(countable, uncountable) A locale in the United States. ▸ An unincorporated community in West Virginia.
(countable, uncountable) A village in Subcarpathia, Poland.