Re: The oddness of Gaelic words in p-

> A nice little Latin derivational system was borrowed by British
> Celtic, namely *pex- 'to sin' (pecca:re), *pexOd 'a sin' (pecca:tu-),
> *pexOdr, *pexadyr a sinner' (pecca:tor, pecca(:)to:rem). While the
> reflexes of the agent noun suffix *-Odr, *-adyr became somewhat
> productive in W, this did not happen in SWBrit., which is why a back-
> formation (noun -> verb) seems unlikely.

Yes, slightly different sources for Welsh, Cornish and Breton:

Welsh, Cornish pechadur > Vulgar Latin peccato:rem
Middle Breton pechezr > Classical Latin pecca:tor

There is also a later, alternate Welsh form, pechodwr "sinner", which
is actually a combination of pechod "sin" (L. pecca:tum) and Brittonic
*uiros "man".

- Chris Gwinn