Webster's Revised Unabridged Dictionary · 1913

Fenian

Fenian , noun

[From the Finians or Fenii, the old militia of Ireland, who were so called from Fin or Finn, Fionn, or Fingal, a popular hero of Irish traditional history.]

A member of a secret organization, consisting mainly of Irishmen, having for its aim the overthrow of English rule in Ireland.

Fenian , adjective

Pertaining to Fenians or to Fenianism.