somniferous is a word that can be used mainly at school, college or office. The ambience at these places are somniferous(atleast to me) so, somniferous means
Insouciant : The class was insouciant about teacher presence.
distraught: seeing my slary, not only i felt irated but distraught as well.
nausea : since i wanted to bunk my class, i said i am feeling like nausea.
soporific : Darn! i am feeling soporific again.