One who opposes another; one who works or takes a position against someone or something; one who attempts to stop the progress of someone or something.
The participant who opens an academic debate by putting forward objections to a theological or philosophical thesis.
One who opposes another in words (in a dispute, argument or controversy).
One who is opposed or objects (to a policy, course of action or set of ideas).
One who opposes another physically (in a fight, sport, game, or competition).
One who veers with every change of current opinion; a fickle, inconstant person.
A weather vane, sometimes in the form of a cockerel.
A kind of wind pump whose top behaves like a weather vane, moving with the wind direction, but which also has a wheel attached to measure wind speed.
To act as a weathercock for.
To turn upwind because of the difference in water pressure on two sides.
To veer into the direction of the oncoming (relative) wind.