Reconstruction talk:Proto-Celtic/udenskyos

Source?
What is the source for this reconstruction? Is there any clue as to the origin of the suffix *-skyos? --85.149.78.152 17:30, 23 December 2020 (UTC)
 * The source is the Etymological Dictionary of Proto-Celtic (R:cel:EDPC). The author says, "Although this etymology is often repeated in handbooks, I am not absolutely certain that it is correct. The suffix combination *-skyo- seems odd. Another possibility is to posit *ud-es-kyo- (cf. the s-stem in Gr. dial. 'water' and cf. Skt.  'well')." —Mahāgaja · talk 18:23, 23 December 2020 (UTC)