1. [n]  forceful prevention; putting down by power or authority; "the suppression of heresy"; "the quelling of the rebellion"; "the stifling of all dissent"
2. [adj]  characterized by oppressive heat and humidity; "the summer was sultry and oppressive"; "the stifling atmosphere"; "the sulfurous atmosphere preceding a thunderstorm"

STIFLING is a 8 letter word that starts with S.