Following up and rephrasing this...
Way back in 1900, the antiquarian H. Munro Chadwick mentioned the
dedication in Chester, England, which is to "I.O. M. Tanaro". Chadwick
remarks about the other inscriptions to Taranus and Taranucus. He also
makes mention that Tanarus corresponds to Thunuraz.
Watkins AHDIER and Pokorny both give the distinct PIE *(s)ten- as the origin of PGmc Thunaraz and such terms as Thunder, Thor, Donner, etc.
Pokorny then gives the seperate PIE *tor- as the origin of the Celtic taran/torann.
Of course AHDIER only gives English roots and so no mention of an etymology for the Celtic taran is made.
On the other hand, in 'An etymological lexicon of Proto-Celtic' by
Matasovic, I found this entry:
Proto-Celtic: *torano- 'thunder' [Noun]
Old Irish: torann [o m and f] 'thunder, noise'
Middle Welsh: taran [f] '(peal of) thunder, thunderclap'
Middle Breton: taran (OBret.) gl. tonitru, MoBret. taran
Cornish: taran gl. tonitruum (OCo.), MCo. taran
Gaulish: Taranis [Theonym]
Proto-Indo-European: *(s)ten-r-
Page in Pokorny: 1021
IE cognates: OHG donar, English thunder
Notes: The Celtic forms are best explained by a
metathesis *tonaro- > *torano-, despite some doubts expressed by LEIA
(s. v.). The unmetathesized form is perhaps attested as the OBrit.
theonym Tanaro and in the old name of the river Po, Tanarus 'thundering'.
References: LEIA T-113, GPC III: 3447, Delamarre 290
Thus Matasovic follows Pokorny and Watkins in saying that PIE *(s)ten-r- is the origin of Thunder/Donner ; and yet Matasovic disagrees with
Pokorny by staing that the Celtic forms do not derive from a distinct
PIE root (*tor-) but rather from a metathesis of *tonaro- > *torano-.
On the other hand, the IE database of Nikolaev and Starostin, gives
Proto-IE: *taron- <PIH *-rH-> as the origin of BOTH the Celtic Taran and the Gmc Thunr/Thunraz; as well as the Hittite Tarhun and other derivatives.
Any ideas on whether Taran and Thunder share a common IE root
(whether that root be *taron- [per Nikolaev and Starostin] or (s)tene- [per Matasovic] )?
Any advice would be greatly appreciated. Thanks!
-Aydan