Pronunciation: (im-pôr'tnt),[key] —adj. 1. of much or great significance or consequence: an important event in world history. 2. mattering much (usually fol. by to): details important to a fair decision. 3. entitled to more than ordinary consideration or notice: an important exception. 4. prominent or large: He played an important part in national politics. 5. of considerable influence or authority, as a person or position: an important scientist. 6. having social position or distinction, as a person or family: important guests. 7. pompous; pretentious: When speaking, he assumes an important attitude that offends his audience. 8. Obs.importunate.