[ groh-muh ]
/ ˈgroʊ mə /

noun (in ancient Roman surveying)

an 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.

Origin of groma

< Latin grōma, grūma, by dissimilation < Greek gnôma, presumably with sense of gnṓmōn carpenter's square; see gnomon Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019