Conforming to the rules of grammar: a grammatical sentence. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "grammatical" in a sentence
"It also made a change on the "Diversity Initiatives" page - a two-letter correction of what it called a grammatical glitch, although others might see it as more of a Freudian slip."
"The Clear Grammar series teaches basic grammatical concepts, provides ample speaking and writing practice in grammatical structures, and serves as a grammar reference that is written with language and terms that students can understand without teacher assistance."
"You seem to be inferring wrongness from my claim that certain grammatical constructions are simply NOT LOGICAL."