in English is:

supertonic

Mutations

Soft:(no mutation)
Nasal:(no mutation)
Aspirate:(no mutation)

Use

yr uwchdonydd hwn
fy uwchdonydd i
dy uwchdonydd di
ei uwchdonydd ef/o
ei huwchdonydd hi
ein huwchdonydd ni
eich uwchdonydd chi
eu huwchdonydd nhw/hwy
External

Dictionary Portal

This is a library of dictionaries and other online resources where you can search further for uwchdonydd*:

Specialist Dictionaries
Glossaries
Terminology
Encyclopedia
Example Sentences
Sentences containing:

*External websites will be opened in a new window.