A quasi-adjective is a word that functions similarly to an adjective but doesn't entirely meet the criteria of one. Some synonyms for quasi-adjective include pseudo-adjective, quasi-descriptive word, and quasi-modifier. Other terms that can be used to describe quasi-adjectives are adjectival nouns, adjectival participles, and adverbial modifiers. These terms refer to words or phrases that convey a description or quality but aren't solely used as adjectives. Quasi-adjectives can be used in a variety of ways, from modifying nouns to creating comparisons and assumptions, and they can be found in many different types of writing, from formal to informal.