Where does “gwall treiglo” come from?

gwall treiglo (Welsh) comes from Welsh gwall, from Middle Welsh gwall, from Proto-Brythonic *gwall, from Proto-Celtic *wolsos — something wrong.

gwall treiglo (Welsh): an incorrect mutation, a mutation error

Definitions

  1. an incorrect mutation, a mutation error

Ancestry of “gwall treiglo”, step by step

gwall treiglo traces back through two separate lines of ancestry.

via Welsh gwall

StepLanguageWordMeaning
1Welshgwallmistake
2Middle Welshgwall—
3Proto-Brythonic*gwall—
4Proto-Celtic*wolsossomething wrong

via Welsh treiglo

StepLanguageWordMeaning
1Welshtreigloto roll, to trundle, to elapse
2Welsh-oused to form pet names; verb suffix for the...
3Middle Welsh-aw—
4Proto-Brythonic-ọβ̃Forms verbal nouns, originally from ā-verbs
Every word from Proto-Celtic *wolsos →Every word from Proto-Brythonic *gwall →Every word from Middle Welsh gwall →