The son of Ruth and Boaz, father of Jesse and grandfather of David, grandson of Naomi. / A male given name from Hebrew of biblical origin.

Initialism of Office of Bilingual Education. / (US politics, historical) Initialism of Office of Business Economics, now BEA. / Initialism of Oregon Board of Education.

Initialism of Officer of the Order of the British Empire. / Initialism of operating-basis earthquake. / Initialism of out-of-body experience. / Initialism of outcome-based education.

Initialism of overcome / overtaken by events (i.e., now obsolete)

(historical) a halfpenny

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

(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.

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

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