From Longman Dictionary of Contemporary Englishtarttart1 /tɑːt $ tɑːrt/ noun 1 
[countable, uncountable]DF a pie without a top on it, containing something sweetapple/treacle/jam etc tart► see thesaurus at taste2 [countable] informalSYSEX/HAVE SEX WITH an insulting word for a woman who you think is too willing to have sex3 [countable] informalSYSEX/HAVE SEX WITH a prostitute
[countable, uncountable]DF a pie without a top on it, containing something sweetapple/treacle/jam etc tart► see thesaurus at taste2 [countable] informalSYSEX/HAVE SEX WITH an insulting word for a woman who you think is too willing to have sex3 [countable] informalSYSEX/HAVE SEX WITH a prostituteExamples from the Corpus
tart• Chill tart until ready to serve.-0-.• I ate my custard tart like this.• To use as a filling, drain the fruit and fill crepes or individual tarts.• Cream of the crop: custard topping adds a crafty touch to Pear tart.• That tart Kat would do for starters.• They were buying Eccles cakes and treacle tart and currant buns and iced tarts with bright-red cherries on top.• He hoped she wouldn't find the sausage and the treacle tart.apple/treacle/jam etc tart• To top things off is an apple tart with caramelized walnuts, and I barely have enough room for my cappuccino.• They were buying Eccles cakes and treacle tart and currant buns and iced tarts with bright-red cherries on top.• As he took it off he remembered the sausage and treacle tart in his pocket.• A white cloth was spread on the table, homemade bread and jam, a fresh apple tart.• Harriet played in tennis doubles and her public school boyfriends crowded in to eat her jam tarts.• She wrote to say that she likes apple tart.• He'd left his sausage and the square of treacle tart she'd put out for his pudding.tarttart2 adjective 1 SOURfood that is tart has a sharp sour taste a tart apple► see thesaurus at taste2 → tart reply/remark etc —tartly adverb ‘I don’t think so!’ she replied tartly. —tartness noun [uncountable]Examples from the Corpus
tart• Red currants are quite tart and usually need sugar or honey.• The Cointreau adds some sweetness, but the cranberry juice is tart as well so the overall effect is a tart drink.• This tart citrus dressing is great on salads.• The girl with the tart tongue?tarttart3 verb → tart something ↔ up→ See Verb tableOrigin tart1 1. (1300-1400) Old French tarte; 2. probably partly from sweetheart tart2 Old English teart “sharp, severe” 