the GNU version of the Collaborative International Dictionary of English
adj. Tending to smother; stifling.
The Century Dictionary and Cyclopedia
Tending to smother; full of smoke, fog, dust, or the like; stifling: as, a smothery atmosphere.
Word Usage
"Sleep on a porch, or in a room with windows on two sides wide open, and the average living-room or office begins to feel stuffy and "smothery" at once."