Why is the ninth month called September?
"mixture of cement," late 13c., from Old French mortier "builder's mortar, plaster; bowl for mixing" (13c.), from Latin mortarium "mortar," also "crushed drugs," probably the same word as mortarium "bowl for mixing or pounding" (see mortar (n.2)). Dutch mortel, German Mörtel are from Latin or French.
"bowl for pounding," c.1300, from Old French mortier "bowl; builder's mortar," from Latin mortarium "bowl for mixing or pounding," also "material prepared in it," of unknown origin and impossible now to determine which sense was original (Watkins says probably from PIE root *mer- "to rub away, harm;" see morbid). Late Old English had mortere, from the same Latin source, which might also be a source of the modern word. German Mörser also is from Latin.
"short cannon," 1550s, originally mortar-piece, from Middle French mortier "short cannon," in Old French, "bowl for mixing or pounding" (see mortar (n.2)). So called for its shape.
mortar mor·tar (môr'tər)
A vessel in which drugs or other substances are crushed or ground with a pestle.
A machine in which materials are ground and blended or crushed.
(Heb. homer), cement of lime and sand (Gen. 11:3; Ex. 1:14); also potter's clay (Isa. 41:25; Nah. 3:14). Also Heb. 'aphar, usually rendered "dust," clay or mud used for cement in building (Lev. 14:42, 45). Mortar for pulverizing (Prov. 27:22) grain or other substances by means of a pestle instead of a mill. Mortars were used in the wilderness for pounding the manna (Num. 11:8). It is commonly used in Palestine at the present day to pound wheat, from which the Arabs make a favourite dish called kibby.