Where does “cystadleuydd” come from?

cystadleuydd (Welsh) comes from Welsh cystadlu, from Welsh -u, from Middle Welsh -u, from Proto-Brythonic -oβ̃ — Forms verbal nouns, originally from thematic...

Ancestry of “cystadleuydd”, step by step

Step	Language	Word	Meaning
1	Welsh	cystadlu	to compete, to vie, to rival
2	Welsh	-u	impression, imprint
3	Middle Welsh	-u	—
4	Proto-Brythonic	-oβ̃	Forms verbal nouns, originally from thematic...

Every word from Proto-Brythonic -oβ̃ →Every word from Welsh -u →Every word from Welsh cystadlu →