M / mortārĭum
noun

mortārĭum

gen. mortārii · gender neuter · decl. 2nd
a mortar
a mortar (mostly ante-class. and post-Aug.).
Lit.: mortarium, in quo teruntur quae solvenda sunt, Non. 543, 22; Plaut. Aul. 1, 2, 17; Cato, R. R. 74: aerea, Plin. 33, 8, 41, § 123: plumbea, id. 34, 18, 50, § 168.—
by extension
A large basin; trough in which mortar is made
A large basin or trough in which mortar is made, Vitr. 7, 3, 10; 8, 6, 14; Plin. 36, 23, 55, § 177.—Hence,
Mortar
Mortar: mortario caementum addatur, Vitr. 8, 7.—
A hollow resembling a mortar
A hollow resembling a mortar, dug round a tree: arbori mortarium statim faciunt, Pall. 4, 8, 1.—
That which is triturated in a mortar, a drug
That which is triturated in a mortar, a drug: et quae jam veteres sanant mortaria caecos, Juv. 7, 170.