any size, esp in clothing, that is halfway between two sizes
WordReference Random House Unabridged Dictionary of American English © 2025
half′ size′,
- Clothingany size in women's garments designated by a fractional number from 12½ through 24½, designed for a short-waisted, full figure.
Collins Concise English Dictionary © HarperCollins Publishers::
'half size' also found in these entries (note: many are not synonyms or translations):