A person who is obnoxious and unattractive to the opposite sex.
I know. He is such a Hannigan.
by Un femme January 24, 2011
An Irish name, it's the shortened Anglicized form of Gaelic Ó hAnnagáin ‘descendant of Annagán’, a pet form of the personal name Annach
Hello' my name is Keenan Hannigan.
by Scatman223 July 10, 2008