O

An abbreviation for Ordinary Seaman. - Latin. n. Mouth, speech, expression, face, pronunciation, opening, source, a mask, face, countenance, sight, expression.

 - n. pl. Ossa a bone.

 - n. pl. Ora A mouth; an opening; an entrance.

 - n. pl. Osar. (Geol.) One of the ridges of sand or gravel found in Sweden, etc., supposed by some to be of marine origin, but probably formed by sub-glacial waters. The osar are similar to the kames of Scotland and the eschars of Ireland. See Eschar.