WEATHERCOCK

Weath″er‐cock′ (?), n. 1. 1. A vane, or weather vane; — so called because originally often in the figure of a cock, turning on the top of a spire with the wind, and showing its direction. “As a wedercok that turneth his face with every wind.” Chaucer.
Noisy weathercocks rattled and sang of mutation. Longfellow. 2. 2. Hence, any thing or person that turns easily and frequently; one who veers with every change of current opinion; a fickle, inconstant person.