Open English Wordnet
Nouns
(n)suppression, crushing, quelling, stiflingforceful prevention; putting down by power or authority“the suppression of heresy”, “the quelling of the rebellion”, “the stifling of all dissent”
Adjectives
(s)sultry, stifling, sulfurous, sulphurouscharacterized by oppressive heat and humidity“the summer was sultry and oppressive”, “the stifling atmosphere”, “the sulfurous atmosphere preceding a thunderstorm”