tart 1 (tärt) adj. tart·er, tart·est 1. Having a sharp pungent taste; sour. See Synonyms at sour. 2. Sharp or bitter in tone or meaning; cutting.
OR you can go with what I was thinking about — because my mind set is always different from yours. And who can blame me…..why think of a lemon when you can eat these delicious tarts…A tart is a baked dish consisting of a filling over a pastry base with an open top not covered with pastry.