Christopher Gwinn wrote:
> A similar process is behind Gaulish gabros "goat"
> (from PIE *kaper, with loss of -e-, an uncommon
> shift of -k- to -g-, and -p- to -b- next to the
> liquid -r-). As a note, it may be that the
> Celtic word for sheep, *cair- (Welsh caer, Irish
> caor, Gaulish Caera-), comes from *kaper as
> well, with loss of internal -p- due to the
> retention of vowel length in the final -e-.
To further confuse matters, Old Irish has masc. "gabor"
meaning "goat", but also a separate word (at least
according to DIL), fem. (either o- or i- stem) "gabor"
meaning "horse, white horse, mare". The latter word
is mainly poetic, but quite well entrenched, and both
words are still found in the modern language.
Incidentally, Irish for "sheep" is "caora; OI cáera",
not to be confused with "caor / cáer" meaning "small
round object; berry", although Thurneysen did once
suggest deriving the former from the latter, naming
the sheep from the shape of its shit!
Dennis King