Opposition, n.
Etymology: [F., fr. L. oppositio. See Opposite.]
1. The act of opposing; an attempt to check, restrain, or defeat; resistance. The counterpoise of so great an opposition. Shak. Virtue which breaks through all opposition. Milton.
2. The state of being placed over against; situation so as to front something else. Milton.
3. Repugnance; contrariety of sentiment, interest, or purpose; antipathy. Shak.
4. That which opposes; an obstacle; specifically, the aggregate of persons or things opposing; hence, in politics and parliamentary practice, the party opposed to the party in power.
4 more senses
5. (Astron.)
The situation of a heavenly body with respect to another when in the part of the heavens directly opposite to it; especially, the position of a planet or satellite when its longitude differs from that of the sun 180º; -- signified by the symbol as, .
6. (Logic)
The relation between two propositions when, having the same subject and predicate, they differ in quantity, or in quality, or in both; or between two propositions which have the same matter but a different form.
Shades of meaning
Fernald has no entry of its own for opposition; he lists it under ambition, antipathy, collision.
Where he writes about it:
Opposition is becoming a frequent substitute for competition in business language; it implies that the competitor is an opponent and hinderer. — from ambition
Antagonism may result from the necessity of circumstances; opposition may spring from conflicting views or interests; abhorrence and detestation may be the result of religious and moral training; distaste and disgust may be acquired; aversion is a deep and permanent dislike. — from antipathy
A natural antipathy may give rise to opposition which may result in hatred and hostility. — from antipathy
Opposition is used chiefly of persons, more rarely of opinions or interests; conflict is used indifferently of all. — from collision