Nouns

(n)fake, sham, postichesomething that is a counterfeit; not what it seems to be
(n)imposter, impostor, pretender, fake, faker, fraud, sham, shammer, pseudo, pseud, role playera person who makes deceitful pretenses

Verbs

(v)simulate, assume, sham, feignmake a pretence of“She assumed indifference, even though she was seething with anger”, “he feigned sleep”
(v)feign, sham, pretend, affect, dissemblemake believe with the intent to deceive“He feigned that he was ill”, “He shammed a headache”

Adjectives

(s)assumed, false, fictitious, fictive, pretended, put on, shamadopted in order to deceive“an assumed name”, “an assumed cheerfulness”, “a fictitious address”, “fictive sympathy”, “a pretended interest”, “a put-on childish voice”, “sham modesty”