pseu·do·bulb 
(sdō-bŭlb′)
(sdō-bŭlb′)n.
A thickened, bulbous portion of the stem in many orchids.
- opponent
- opportune
- opportunely
- opportuneness
- opportunism
- opportunist
- opportunistic
- opportunistic infection
- opportunity
- opposability
- opposable
- oppose
- opposer
- opposite
- opposite field
- opposite-field
- oppositely
- oppositeness
- opposite number
- opposition
- oppositional
- oppositionist
- oppress
- oppression
- oppressive