oppo

n. The act of opening an academical disputation; the proposition of objections to a tenet, as an exercise for a degree. [ Eng. ] Todd. [ 1913 Webster ]

a. [ L. opponens, -entis, p. pr. of opponere to set or place against, to oppose; ob (see Ob-) + ponere to place. See Position. ] Situated in front; opposite; hence, opposing; adverse; antagonistic. Pope. [ 1913 Webster ]

n. 1. One who opposes; an adversary; an antagonist; a foe. Macaulay. [ 1913 Webster ]

2. One who opposes in a disputation, argument, or other verbal controversy; specifically, one who attacks some thesis or proposition, in distinction from the respondent, or defendant, who maintains it. [ 1913 Webster ]

How becomingly does Philopolis exercise his office, and seasonably commit the opponent with the respondent, like a long-practiced moderator! Dr. H. More. [ 1913 Webster ]

Syn. -- Antagonist; opposer; foe. See Adversary. [ 1913 Webster ]

v. t. To suit. [ Obs. ] Dr. Clerke(1637). [ 1913 Webster ]

a. [ F. opporiun, L. opportunus, lit., at or before the port; ob (see Ob-) + a derivative of portus port, harbor. See Port harbor. ] Convenient; ready; hence, seasonable; timely. Milton. [ 1913 Webster ]

This is most opportune to our need. Shak. [ 1913 Webster ]

-- Op`por*tune"ly, adv. -- Op`por*tune"ness, n. [ 1913 Webster ]

n. [ Cf. F. opportunisme. ] The art or practice of taking advantage of opportunities or circumstances, or of seeking immediate advantage with little regard for ultimate consequences. [ Recent ] [ 1913 Webster ]

n. [ Cf. F. opportuniste. ] One who advocates or practices opportunism. [ Recent ] [ 1913 Webster ]

adj. 1. taking immediate advantage, often unethically, of any circumstance of possible benefit; practising opportunism. [ wns=1 ]
Syn. -- opportunist, timeserving. [ WordNet 1.5 ]

2. (Med.) Causing disease only when the immune system of the host has been weakened, or other damage to the host provides special opportunity for invasion; -- of microorganisms or infectious diseases; as, opportunistic pathogens may infect a burn site; AIDS predisposes a patient to opportunistic infection. [ PJC ]