This is an adjective suffix.
iver, winter.
ivernouge, wintry.
-oun (masc.), -ouno (fem.).
A diminutive suffix.
enfan, child.
enfantoun, enfantouno, little child.
pauriho, the poor.
paurihoun, poor wretch.
-ounge (masc.).
A suffix forming nouns from adjectives.
vièi, old.
vieiounge, old age.
-our (fem.).
This is like the above.