[mor.tar] n [ME morter, fr. OE mortere & MF mortier, fr. L mortarium] (bef. 12c) 1: a strong vessel in which material is pounded or rubbed with a pestle
2. [MF mortier] a: a muzzle-loading cannon having a tube short in relation to its caliber that is used to throw projectiles with low muzzle velocities at high angles b: any of several similar firing devices
[2]mortar n [ME morter, fr. OF mortier, fr. L mortarium] (14c): a plastic building material (as a mixture of cement, lime, or gypsum plaster with sand and water) that hardens and is used in masonry or plastering -- mor.tar.less adj [3]mortar vt (14c): to plaster or make fast with mortar