Synonyms of insincere

1 Syllable

fake, sly, slick, faux, glib

2 Syllables

smarmy, untrue, southpaw, phony, glibber, feigned, unreal, devious, double, glibbest, hot-air, lying, put-on, canting, tinsel, snide, shifty, faithless, jivey, too-too, false, mincing, forced, hollow

3 Syllables

deceitful, fulsome, left-handed, two-faced, untruthful, storybook, pretentious, lefthanded, backhanded, perfidious, fast-talking, smooth-tongued, dissembling, pecksniffian, unfaithful, pharisaic, mendacious

4 Syllables

meretricious, double-dealing, unconforming, ambidextrous, duplicitous, ambilevous, sanctimonious, deceptive, evasive, disingenuous, vocative, mealymouthed, pharisaical, unnatural, oleaginous

5 Syllables

dissimulating, hypocritical