Girlish means having the manner of a young girl. A girlish laugh, girlish enthusiasm, girlish handwriting.
Said of a grown woman it belittles, since the point is that she is not one, and that is worth knowing before using it. Of an actual girl it is simply descriptive and rather warm.
1adjectivegirlishHaving the manner of a young girl.
“My grandmother gave a girlish giggle when the young doctor complimented her.”
girlish is a quality.
Middle English
girle
English
girl
English, today
girlish
Built from
From girl + -ish. girl comes from Middle English girle. From Middle English gerle, girle, gyrle (“young person (boy or girl)”), perhaps from Old English gyrele, from Proto-West Germanic gurilā, from a zero-grade diminutive of gaurā + -ilā. Ultimately of unknown origin. a doublet of gal/gyal and gyaru. 2
Etymology from Wiktionary, CC BY-SA