pre·bi·ot·ic 
(prē′bī-ŏtĭk)
(prē′bī-ŏtĭk)adj.
Of or relating to the conditions prevailing on earth before the appearance of living things.
- 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
- oppressively