in English is:

viability

Mutations

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

Use

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

Dictionary Portal

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

Specialist Dictionaries
Glossaries
Terminology
Encyclopedia
Example Sentences
Sentences containing:

*External websites will be opened in a new window.