English Vocabulary Flash Cards @ englishpdf.com and englishteststore.com File 309 insignificant (adj) Without importance, force, or influence insinuate (v) To imply insipid (adj) Tasteless insistence (n) Urgency insistent (adj) Urgent insolence (n) Pride or haughtiness exhibited in contemptuous and overbearing treatment of others insolent (adj) Impudent insomnia (n) Sleeplessness