The name Lleu is derived from Proto-Celtic * Lugus, the exact meaning ( and etymology ) of which is still a matter of scholarly debate.

Proto-Celtic * Lugus may equally be related to Proto-Celtic * lug-meaning " oath, pledging, assurance " on the one hand and " deceive " on the other ( derived from Proto-Indo-European * leugh-‘ avowal, deception ’).

The reconstructed Proto-Celtic lexica at the universities of Leiden and Wales suggest that this name may be derived from Proto-Celtic * Ad-bej-ānos, literally meaning at-striking-related-one and possibly denoting the concept of harp-strumming.

Ptolemy's 2nd century Geographia shows that in antiquity the river's name was Bubindas, which may derive from Proto-Celtic * Bou-vindā, " white cow ".

All the same, Proto-Celtic had * alamo-‘ treasure, asset ’ and, if the alternation Alaunus ~ Alauna represents the Gaulish and Romano-British pronunciation of a derived adjective * alamo-n-o-( treasure-ADJ. SUFF-GEN -), it may have carried the sense of ‘ rich, opulent, fecund, etc .’

Irish Danu is not identical with Vedic Dānu but rather descends from a Proto-Celtic * Danona, which may contain the suffix-on-also found in other theonyms such as Matrona, Maqonos / Maponos and Catona.

The name " Arianrhod " ( from the Welsh arian, " silver ," and rhod, " wheel ") may be cognate with Proto-Celtic * Arganto-rotā, meaning " silver wheel.

The name may also be related to Old Irish lug " lynx ", perhaps indicating the existence of a Proto-Celtic root that denoted an animal with " shining eyes ", from PIE * leuk-" to shine " ( compare Greek lunx " lynx ", perhaps from a zero-grade form * luk-with infixed nasal ).

The name may be composed of the Proto-Celtic prefix * ambi-(' around ') and root * sagro -.

This name may be derived the Proto-Celtic theonym * Φanon -.

However, a cursory glance at the Proto-Celtic lexicon reveals that * belatu-is reconstructible for Proto-Celtic with the meaning ‘ death ’ and that * kadro-is a reconstructible element meaning ‘ decorated .’ So the name Belatucadros may also be interpreted as a compound of two Gallic words descended from two Proto-Celtic elements * belatu-and * kadro-which together as a compound adjective would literally mean ‘ death-decorated .’ Indeed, this is hardly an original proposal for the meaning of the name of this god associated with Mars: MacCulloch as early as 1911 ( p135 ) glossed this god ’ s name as ‘ comely in slaughter ’.

The name Contrebis may possibly contain a root related to Proto-Celtic trebo-' house '.

That of Ialonus may be related to the Proto-Celtic root jalo-' clearing '.

It was once thought that the root may be derived from Proto-Indo-European " to shine ", but there are difficulties with this etymology and few modern scholars accept it as being possible ( notably because Proto-Indo-European never produced Proto-Celtic ).

Proto-Celtic is reconstructed as having * werbā-' blister ' in its lexicon and the name may be a suffixed form of this lexeme meaning “ blistered one .” On the other hand, the root of the name may represent a Celtic reflex of the Proto-Indo-European root * wer-bhe-‘ bend, turn ,’ cognate with Modern English warp, followed by the durative suffix *- j-and the feminine suffix *- ā-and so might have meant “ she who is constantly bending and turning .” Another possibility is that the name is a compound of Romano-British reflexes of the Proto-Celtic elements ** Uφer-bej-ā-( upper-strike-F ) “ the upper striker .”

Both names are considered P-Celtic and may be derived from a Proto-Celtic root * mano-( alternately * meno-or * mono -) meaning either " thought " or " treading " ( another possibility being a derivative of another root * mono -, from Proto-Indo-European * men-meaning " to tower ", which gives us the Brythonic words for " mountain ").

The name may be Celtic and generic title for a prophetess ( from Proto-Celtic * welet-" seer ", a derivative of the root * wel-" to see ").

This can be reconstructed in Proto-Celtic as * Moro-rīganī-s.

It appears, therefore, that in Proto-Celtic the first month of the summer season was named ' wintry ', and the first month of the winter half-year ' summery ', possibly by ellipsis, ' at the end of summer / winter ', so that samfuin would be a restitution of the original meaning.

In Celtic polytheism, the name of the oak tree was part of the Proto-Celtic word for ' druid ': * derwo-weyd-> * druwid-; however, Proto-Celtic * derwo-( and * dru -) can also be adjectives for ' strong ' and ' firm ', so Ranko Matasovic interprets that * druwid-may mean ' strong knowledge '.

It would then be only a coincidence that it resembles the Proto-Celtic verb reto (" to run ").

The name could be interpreted as an extended form of a stem composed of Proto-Celtic elements deriving from Proto-Indo-European roots * ad-‘ to ’ + either * bʰend-‘ sing, rejoice ’ or * bʰendʰ-‘ bind ’.

This name appears to be derived from Proto-Celtic * Hek-to-landā.

This theonym appears to be derived from Proto-Celtic * Ad-sūg-lat-ā.

This theonym appears to be derived from Proto-Celtic * Oibel-ā.

This name appears to be derived from Proto-Celtic * aidu-mandā.

Old Church Slavonic plavu, Lithuanian palvas ‘ sallow ,’ Greek polios, Latin polus ' brilliant white ,' Welsh llwyd ‘ gray ’ and Irish liath from Proto-Celtic * φleito-s, Latin pallere ‘ to be pale ’ and hence also cognate with words for ‘ pigeon ’ as Greek peleia, Latin palumbes and Old Prussian poalis.

The ethnonym would then be etymologically related to words as Latin venus ,-eris ' love, passion, grace '; Sanskrit vanas-' lust, zest ', vani-' wish, desire '; Old Irish fine (< Proto-Celtic * venjā ) ' kinship, kinfolk, alliance, tribe, family '; Old Norse vinr, Old Saxon, Old High German wini, Old Frisian, Old English wine ' Friend '.

Veteris may possibly be related to the Proto-Celtic root * weto-meaning ' air ' or * wī-ti-meaning ' food '.

The name ' Latis ' may conceivably be related to the Proto-Celtic words * lati-meaning ' liquor ', * lat-' day ', or * lāto-' lust '.

If it is read as Satiada, the name may conceivably be related to the Proto-Celtic * sāti-‘ saturation ’ or * satjā-‘ swarm ’.

Conceivably it might be related to the Proto-Celtic * seno-' old '.

It may be possible that the name ' Ancasta ' is related to Proto-Celtic * kasto-meaning ' swift '.

The name Mabon is derived from the Common Brythonic and Gaulish deity Maponos, meaning "( Divine ) Son ", from the Proto-Celtic root * makwo-" son ".

The word is a loanword from Scottish Gaelic, deriving from Proto-Celtic * bardos, ultimately from Proto-Indo-European * g < sup > w </ sup > rh < sub > 2 </ sub >- dh < sub > 1 </ sub >- ó -, from the root * g < sup > w </ sup > erh < sub > 2 </ sub > " to raise the voice ; praise ".

Along these lines, the name would mean ‘( the god ) who sings to ( something / someone )’ or ‘( the god ) who binds ( something / someone ) to ( something / someone ).’ However, it is also possible to see the name as an extended form of a variant form of the Proto-Celtic word * abon-‘ river ,’ derived from the Proto-Indo-European root * ab -, * h₂eb-‘ water, river ’.

The root Alisa-of the name Alisanus is phonologically comparable to the Proto-Celtic * alisā, ‘ alder ’.

This etymology has been dismissed because Proto-Indo-European * k did not under any known circumstances become * g-in Proto-Celtic, but remained * k. The direct descendent of the Proto-Indo-European root * leuk-(‘ white light ’) in Proto-Celtic is * leuk-as in the name of the Celtic lightning god Leucetios.

Derivation from a Proto-Celtic root * granno-‘ beard ’ ( cf.

Ranko Matasović, in his Etymological Dictionary of Proto-Celtic, has tentatively proposed that the root of this theonym comes from Proto-Celtic * g < sup > w </ sup > renso -, which means " heat ";< ref > R.

The Proto-Celtic root of the name,, is generally believed to have been derived from one of several different Proto-Indo-European roots, such as " black ", " to break ", and " to swear an oath ",

Squire ( 2000: 45 ) glossed the name as ' venomous ' presumably relating it to the Proto-Celtic * nemi-‘ dose of poison ’ ‘ something which is dealt out ’ from the Proto-Indo-European root * nem-‘ deal out ’ ( Old Irish nem, pl.