- a member of an Irish revolutionary organization founded in New York in 1858, which worked for the establishment of an independent Irish republic.
- (in late Irish legends) a member of a group of warriors always ready to defend Ireland against its enemies.
- (formerly) a member of an Irish revolutionary organization founded in the US in the 19th century to fight for an independent Ireland
- one of the Fianna
- an Irish Catholic or a person of Irish Catholic descent
- of or relating to the Fenians
