Pour le grec :
Greek: λυκάβας, -αντος
Etymology: Etymologically quite unclear (on the formation Chantraine Form. 269, Schwyzer 526). The explanations are not very convincing: prop. "light-circle", from *λύκ- `light' (s. on λύχνος) and ἄβα τροχός H. (Fick GGA 1894, 240, Bechtel Lex. s. v., v. Blumenthal ZONF 13, 157); prop. "Lycianking (-priest, -god)", i.e. Apollon, elliptically for `feast of Apollon', lydian word like βασιλεύς (Fraser Streitberg-Festgabe 93ff.); prop. "wolfs-run" (E. Maaß IF 43, 259ff.); prop. "religion" (Theander Symb. Danielsson 349ff.). Cf. the remarks by Kretschmer Glotta 15, 198f.; 17, 214; 22, 262. - (Not here Λυκαβηττός.) The variant with μ and the suffix -αντ- show a Pre-Greek word.
Greek: λύκος
Origin (see intro): Indo-European [1178] *u̯l̥kʷos `wolf'
Etymology: With λύκος agrees formally exactly the Northgerm. name of the lynx, Swed. lō (PGm. *luha- from IE *luko-; s. 2. λύγξ). But of course one prefers to connect the widespread name of the wolf, which is preserved e. g. in Skt. vŕ̥ka-, Lith. vil̃kas, OCS vlьkъ, Goth. wulfs, Alb. ulk. With the resulting IE *u̯l̥kʷos can λύκος be combined if we assume, that the labiovelar coloured the preceding sonant with loss of the labialisation, cf. Schwyzer 298 and 352; s. also on κύκλος. A comparable problem gives Lat. lupus. Far remains however Arm. gayl (rather to Ir. gāel `wolf' with Fick 2, 259 a. o.). With the name of the wolf taboo-ideas may have played a part (Havers Sprachtabu 37ff.) which may have caused phonetic irregularities. Also for IE *u̯l̥kʷos such an origin is possible; the interpretation as `lacerater' (to u̯el(k)- `lacerate' not counting the labiovelar; s. Specht KZ 66, 26f.) remains hypothetic. - Details in WP. 1, 316f., Pok. 1178f., W.-Hofmann s. lupus, Vasmer s. volk; also Benveniste BSL 44, 53.
(source : Greek etymological dictionary; par Robert Brill)
Le dictionnaire étymologique de la langue grecque par Chantraine dit la même chose, mais en français ici.
Donc pour résumer, l'étymologie de lycabas étant incertaine, certains le rapprochent de lycos et d'autres non.
Pour les langues celtiques, tu trouveras peut-être ton bonheur ici (il ne donne pas les racines mais des rapprochements avec le grec et le latin donc à partir de là on peut essayer de chercher la racine indo-européenne), ou là.