the.com/stuffy
When a room and a personality share the same lack of fresh air.
means Either poorly ventilated and airless, or stiffly formal and humorlessly conventional in attitude.
from From stuff plus the airy -y suffix; the literal sense of an over-packed, breathless room drifted by the 1800s into describing equally suffocating personalities.
Two meaningsBlocked sinuses and blocked sense of humor.
Nasal cousinA stuffy nose stuffs nothing, yet feels packed.
Insult rangeApplies to attics, aristocrats, and bureaucracies alike.