Goidelic

[goi-del-ik] /gɔɪˈdɛl ɪk/
adjective
1.
of or belonging to Goidelic; Q-Celtic.
noun
2.
Also called Q-Celtic. the subbranch of Celtic in which the Proto-Indo-European kw -sound remained a velar. Irish and Scots Gaelic belong to Goidelic.
Also, Gadhelic.
Compare Brythonic, P-Celtic.
Origin
1880-1885; < Old Irish Goídil Gael + -ic
British Dictionary definitions for Goidelic

Goidelic

/ɡɔɪˈdɛlɪk/
noun
1.
the N group of Celtic languages, consisting of Irish Gaelic, Scottish Gaelic, and Manx Compare Brythonic
adjective
2.
of, relating to, or characteristic of this group of languages
Word Origin
C19: from Old Irish Goidel a Celt, from Old Welsh gwyddel, from gwydd savage
Word Origin and History for Goidelic
adj.

"pertaining to the branch of Celtic languages that includes Irish, Gaelic, and Manx," 1882, coined by Sir John Rhys (and first used in his "Celtic Britain"), from Old Irish Goidel "Gael" (see Gael).