'Granduncle' definitions:

Definition of 'granduncle'

(from WordNet)
noun
An uncle of your father or mother [syn: great-uncle, granduncle]

Definition of 'Granduncle'

From: GCIDE
  • Granduncle \Grand"un"cle\, n. [Cf. F. grand-oncle.] A father's or mother's uncle. [1913 Webster] grand unified theory