word class part of speech https://en.wikipedia.org/wiki/Category:Parts_of_speech https://en.wikipedia.org/wiki/Part_of_speech A category of words (or, more generally, of lexical items) that have similar grammatical properties. Words that are assigned to the same part of speech generally display similar syntactic behavior—they play similar roles within the grammatical structure of sentences—and sometimes similar morphology in that they undergo inflection for similar properties. POS PoS parts of speech