WordReference Random House Unabridged Dictionary of American English © 2026
gro•ma
(grō′mə),USA pronunciation n. (in ancient Roman surveying)
- Surveying, Antiquityan instrument having a cruciform wooden frame with a plumb line at the end of each arm, used for laying out lines at right angles to existing lines.
- Greek gnôma, presumably with sense of gnó̄mōn carpenter's square; see gnomon
- Latin grōma, grūma, by dissimilation