Originally Posted by cmacq
Here my knowledge is indeed limited and I do have a simple mind, thus I'm not actually sure how you arrived at 'Best in battle,' for Catu-vellauni? Yet, if one takes the possible first element of Veru-lam-ium, one may find (I) fearr or air [as in Fer-gus], (OI) for, ferr, or vers, (OW/OB) guor, (Breton) voar and oar, (Gaulish) ver, vero, and viro, (Welsh) goreu, (OP) wirst, (Lithuanian) wirzus all meaning; top, raised up, better, best, foremost, most high, and/or of superior standing. The second element is also of some interest as it appears similar to (I) lamh, (OI) lam, (Welsh) llaw, (Cornish) lof, (OB) lau, lama, or plama meaning hand. Now, there is air-lamh; literally high-hand, to-hand; meaning ready. So, Veru-lam-ium may mean 'place of high authority?' Then by extension a possible Catu-verulamus could mean 'Best in Battle' or better still 'Battle Ready.'
Unfortunately, I'm no closer to how you arrived at 'Best in battle' for Catuvellauni. The only possibility I can see for the second element in Catu-vel-laun-i is (OI) fail, fel, fil, with a root of vel or val; meaning to wish or prevail. Now, the Old Irish fail or foil can mean a ring or circle, again from the vel root, which also can mean a circle or ring, as well as to cover or encircle. Here, we also have the Welsh gwal. The third element laun may be related to Ian, (OI) lan, (Welsh) llawn, (OW) laun, (Cornish) leun or len, (Breton) leun or lano meaning full.
I'm sure I've made a great mistake somewhere, but the name Catu-vellauni seems to mean something like 'battle drawn full circle?' Again, If so, I may suggest this could apply to a certain aspect of the patron deity [possibly The Battle Ender] of a given ruling faction within this polity?