in English is:

usefulness

,

utility

Mutations

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

Use

y defnyddioldeb hwn
fy nefnyddioldeb i
dy ddefnyddioldeb di
ei ddefnyddioldeb ef/o
ei defnyddioldeb hi
ein defnyddioldeb ni
eich defnyddioldeb chi
eu defnyddioldeb nhw/hwy
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