mind, so Irish, Old Irish, aicned: ád-gn-eto-, root gna$$-, know, Greek $$Ggignw/skw, English know. Stokes refers it to the root of ++aicme, as he gives it. Ascoli makes the root cen, as in cineal. The Gaelic g is against any root with c.
Etymological dictionary of the Gaelic language.
Alexander Gairm Publications.
1982.