The Collaborative International Dictionary of English v.0.48:

Gadhelic \Ga*dhel"ic\ (g[.a]*d[e^]l"[i^]k; g[a^]d"el*[i^]k), a.
   [See Gael.]
   Of, belonging to, or designating, that division of the Celtic
   languages which includes the Irish, Gaelic, and Manx.
   [Webster 1913 Suppl.]