2. Noun. (grammar) A construction showing an equal quality. In English, this is normally formed using as. For example, the equative of ''happy'' is ''as happy as''. ¹
3. Noun. (grammar) A word in the equative form. ¹
4. Noun. (grammar) A grammatical case in certain languages, including Ossetic, Finnish and Sumerian, that indicates something is like something else. English equivalents include ''he was the same age as her'' and ''he looks like him''. ¹
¹ Source: wiktionary.com