A disloyal person who betrays or deserts a cause, religion, political party, friend, etc.
An outlaw or rebel.
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.