\ JAK-uh-bin \ , noun;
1.an extreme radical, especially in politics.
2.(in the French Revolution) a member of a radical society or club of revolutionaries that promoted the Reign of Terror and other extreme measures, active chiefly from 1789 to 1794: so called from the Dominican convent in Paris, where they originally met.
3.a Dominican friar.
4.(lowercase) one of a fancy breed of domestic pigeons having neck feathers that hang over the head like a hood.