HP Sassoon(1) 200.8 :אית בה דוכתא דמטמטם ולא קא עייל זיקא בגוה ולא משמשא זיקא בגוה‏ : there is a stopped up place in it and the wind does not come into it and it does not enable the wind to come into it
See the entire entry for šmš vb. D to serve