O

obloquy - noun state of disgrace resulting from public abuse; a false accusation of an offense or a malicious misrepresentation of someone's words or actions
obsequious - adj. attentive in an ingratiating or servile manner;attempting to win favor from influential people by flattery
opportunist - adj. taking immediate advantage, often unethically, of any circumstance of possible benefit; noun a person who places expediency above principle
opt - verb select as an alternative; choose instead; prefer as an alternative