Gram*mat"ic*al (?), a. [L. grammaticus, grammaticalis; Gr. &?; skilled in grammar, knowing one's letters, from &?; a letter: cf. F. grammatical. See Grammar.] 1. Of or pertaining to grammar; of the nature of grammar; as, a grammatical rule.

2. According to the rules of grammar; grammatically correct; as, the sentence is not grammatical; the construction is not grammatical.

--Gram*mat"ic*al*ly, adv. -- Gram*mat"ic*al*ness, n.

• (Linguistics) Acceptable as a correct sentence or clause as determined by the rules and conventions of the grammar, or morpho-syntax of the language.
  
• Ungrammatical