This seems the least difficult explanation of this strange name. An alternative theory is that it = Cenomanni (a Gallic tribe-name also found in Lombardy). But with this name (which must have been well known to Caesar) we never again meet in Britain. And it is hard to believe that he would not mention a clan so important and so near the sphere of his campaign as the Iceni.
See p. 109.
These tribes are described by Vitruvius, at the Christian era, as of huge stature, fair, and red-haired. Skeletons of this race, over six feet in height, have been discovered in Yorkshire buried in "monoxylic" coffins; i.e. each formed of the hollowed trunk of an oak tree. See Elton's 'Origins,' p. 168.