'thibs pa

'thibs pa, 'thibs pa, 'thibs pa intr. v.; together, to condensate, to grow dark or dim, dark, close, dense [RY]

be covered, darkened, fogginess [JV]

(to be) torpid; torpor [RB]

1) cloudy, unclear; 2) gather, condense; 3) dim [grow] dark; 4) close, dense [IW]