Strong's Definition
perhaps from 3564; lime (from being burned in a kiln)
KJV Usage: chalk(-stone)
STEPBible — Tyndale Abridged Hebrew Lexicon
גִּר (gir) — chalk. chalk, lime Aramaic equivalent: gir (גִּיר "plaster" H1528)
UBS Dictionary of Biblical Hebrew
noun m
Stone
chalk = a white soft earthy limestone, formed from the skeletal remains of sea creatures
UBS Dictionary of Biblical Hebrew © United Bible Societies, licensed CC BY-SA 4.0.
Brown-Driver-Briggs Hebrew Lexicon
גִּר n.[m.] chalk, lime Is 27:9. ref