Why the ending is -ous when it says us
composedTwo of the word's problems answered at once, the vowel and the ending, in a single spelling.
heard asglaucas
spelledglaucous
saidGLAW-kus
glaucous.
That -ous suffix marks an adjective, and it says us in every word that carries it: famous, nervous, jealous, porous. The o has been silent for centuries and stays on the page as the sign of what kind of word this is.
The other five