Yup, the first Wild Geese were the aristocrats, but the term was later used for the sons of the Catholic aristocracy who headed into military service with France and Spain and Austria, and then later again to other flights of Irish emigrants.

Seagull in Irish is derived from an old name for a wolf; literally the name - Faolain or Faolog (with an accent on the second a or the second o respectively) means "little wolf".