"Grammatical category" refers to a set of meanings or properties that words can express in a particular language. Some synonyms for this term might include "part of speech," "lexical category," or "syntactic category." These phrases all refer to the same basic concept, which is the way that words are classified based on their function and form within a sentence. Other related terms might include "morphological category," which refers to the way that words vary in form based on grammatical information like tense, gender, or number. Overall, the study of grammatical categories is an important aspect of linguistic analysis, as it helps us to understand how language works and how it can be used to convey meaning.