Nouns

(n)tarta small open pie with a fruit filling
(n)tarta pastry cup with a filling of fruit or custard and no top crust

Adjectives

(s)lemony, lemonlike, sourish, tangy, tarttasting sour like a lemon
(s)sharp, sharp-worded, tartharsh“sharp criticism”, “a sharp-worded exchange”, “a tart remark”