How do you spell Tart

Available Definitions:
1)  v. t. - Sharp to the taste; acid; sour; as, a tart apple.
2)  v. t. - Fig.: Sharp; keen; severe; as, a tart reply; tart language; a tart rebuke.
3)  n. - A species of small open pie, or piece of pastry, containing jelly or conserve; a sort of fruit pie.