the word 'tart' entered english in the 14th century from the middle french 'tarte', referring to a type of pastry. its ultimate origins are obscure but may trace back to the late latin 'tarta'. the adjective sense, describing a sharp taste, emerged in the late 14th century, directly from the sensory experience of the food. the figurative use, meaning a sharp or cutting remark, developed later by metaphorical extension from the taste adjective, linking sensory acidity to verbal bitterness.

this word is a simplex form. it is a loanword from middle french 'tarte', of uncertain ultimate origin, possibly from late latin 'tarta'. its functional role is as a complete lexical unit.