Where does “gwycbys” come from?

gwycbys (Welsh) comes from Welsh pys, from Middle Welsh pys, from Proto-Brythonic *pɨs, from Latin pīsum, from Ancient Greek πίσον, from Ancient Greek πίσος — pea, pease, seed of "Pisum sativum".

gwycbys (Welsh): vetch (Vicia)

Definitions

vetch (Vicia)

Ancestry of “gwycbys”, step by step

gwycbys traces back through two separate lines of ancestry.

via Welsh pys

Step	Language	Word	Meaning
1	Welsh	pys	peas
2	Middle Welsh	pys	—
3	Proto-Brythonic	*pɨs	—
4	Latin	pīsum	pea, pease
5	Ancient Greek	πίσον	Quoted by comic poet Alexis; pea, pease, seed of...
6	Ancient Greek	πίσος	pea, pease, seed of "Pisum sativum"

via Welsh gwŷg

Step	Language	Word	Meaning
1	Welsh	gwŷg	vetches (Vicia)
2	Middle Welsh	gwyc	—
3	Proto-Brythonic	*gwɨg	—
4	Latin	vicia	vetch
5	Middle Low German	Wicke	—

Every word from Ancient Greek πίσος →Every word from Ancient Greek πίσον →Every word from Latin pīsum →