Alternative form of obs (obsolete)

Abbreviation of obsolete (as a gloss for words in dictionaries) / Abbreviation of observed

(music) Abbreviation of oboe.

Abbreviation of obstetrics.

(historical) a halfpenny

(archaic) an objection / (genetics) the obese gene

A river in Russia; the westernmost of the three great Siberian rivers.

(category theory) The set of objects of a category.

(non-productive) Against; facing; a combining prefix found in verbs of Latin origin. / (botany) Of a reversed shape.

(Internet, informal, humorous) Obligatory; prepended to the name of a topic being mentioned to avoid accusations of being off-topic.