Entry 1 sense Webster, 1913 Avuncular /əv-ŭng'-kyəl-ẽr/ · A·vun·cu·lar · IPA /əˈvʌŋkjʊlɚ/ 01 a. Of or pertaining to an uncle. 1. Of or pertaining to an uncle. “In these rare instances, the law of pedigree, whether direct or avuncular, gives way.” — I. Taylor.