say it: MAWR-tur
mortar is a noun and verb meaning "a muzzle-loading high-angle gun with a short barrel that fires shells at high elevations for a short range". It carries 4 recorded senses.
a muzzle-loading high-angle gun with a short barrel that fires shells at high elevations for a short range
used as a bond in masonry or for covering a wall
a bowl-shaped vessel in which substances can be ground and mixed with a pestle
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for mortar come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.