悶

stuffy / shut indoors / to smother / to cover tightly

bored / depressed / melancholy / sealed / airtight / tightly closed

heart / mind / intention / center / core / CL:顆|颗[ke1],個|个[ge4]

gate / door / CL:扇[shan4] / gateway / doorway / CL:個|个[ge4] / opening / valve / switch / way to do something / knack / family / house / (religious) sect / school (of thought) / class / category / phylum or division (taxonomy) / classifier for large guns / classifier for lessons, subjects, branches of technology / (suffix) -gate (i.e. scandal; derived from Watergate)

depressed / sulky / moody / unhappy

oppressive (of weather) / heavy / depressed / not happy / (of sound) dull / muffled

sultry / sultriness / hot and stuffy / stifling hot

to feel oppressed / to be depressed / to feel dejected

depressed / gloomy

alcohol drunk to drown one's sorrows

muffled thunder / (fig.) sudden shock / blow

(coll.) outwardly cold or retiring but deep and passionate inside

depressed / full of worries / feeling down

(coll.) to wonder secretly / to make wild conjectures

to divert oneself from melancholy

to divert one's mind from boredom (idiom)

to divert oneself from melancholy

to faint / to swoon / to lose consciousness

lit. to eliminate worry and dispel melancholy (idiom); diversion from boredom / to dispel depression or melancholy / to relieve stress / a relaxing pass-time

silent fart

to keep silent

muffled

to amass wealth while keeping a low profile (idiom)

lit. closed gourd / fig. enigma / complete mystery / taciturn person