о-

• об- (ob-) (before vowels)
• обо- (obo-) (before certain consonant clusters)

From Proto-Slavic *o(b), from Proto-Indo-European *h₃ebʰi.

• IPA^(key): [ɐ]
• IPA^(key): [ˈo] (when stressed)

о- • (o-)

1. prefix added to adjectives or nouns to produce factitive verbs in conjunction with -ить (-itʹ), i.e. verbs with the meaning of making (someone or something) the mentioned characteristic or property

   • See -ить (-itʹ) for examples.

2. prefix added to adjectives or nouns to produce fientive verbs in conjunction with -ить (-itʹ) + -ся (-sja) or with -еть (-etʹ), i.e. verbs with the meaning of becoming or receiving the mentioned characteristic or property

   ‎о- (o-) + ‎зо́лото (zóloto, “gold”) + ‎-и́ть (-ítʹ) + ‎-ся (-sja) → ‎озолоти́ться (ozolotítʹsja, “to receive gold; (figuratively) to get rich”)

   ‎о- (o-) + ‎зелёный (zeljónyj, “green”) + ‎-ить (-itʹ) + ‎-ся (-sja) → ‎озелени́ться (ozelenítʹsja, “to become green; to become planted”)

   ‎о- (o-) + ‎безлю́дный (bezljúdnyj, “uninhabited, depopulated”) + ‎-еть (-etʹ) → ‎обезлю́деть (obezljúdetʹ, “to become depopulated”)

3. prefix added to verbs of motion: about, around

   ‎обо- (obo-) + ‎-йти́ (-jtí, “to go”) → ‎обойти́ (obojtí, “to go around”)

4. prefix added to nouns: close by, around

   ‎о- (o-) + ‎край (kraj, “land, country”) + ‎-ина (-ina) → ‎окра́ина (okráina, “outskirts, periphery”)

   ‎о- (o-) + ‎бок (bok, “side”) + ‎-ина (-ina) → ‎обо́чина (obóčina, “roadside, curb”)

5. prefix added to verbs: completely, to the full extent
6. prefix added to verbs, with the suffix -ся (-sja): to fail at (some action)

   ‎о- (o-) + ‎говори́ть (govorítʹ, “to speak”) + ‎-ся (-sja) → ‎оговори́ться (ogovorítʹsja, “to make a slip of the tongue”)

7. prefix added to verbs, with the suffix -ся (-sja): to recover from (some action)

   ‎о- (o-) + ‎ду́мать (dúmatʹ, “to think”) + ‎-ся (-sja) → ‎оду́маться (odúmatʹsja, “to change one's mind”)

   ‎о- (o-) + ‎по́мнить (pómnitʹ, “to remember”) + ‎-ся (-sja) → ‎опо́мниться (opómnitʹsja, “to regain consciousness”)

• о (o), об (ob)