Pulmonary embolism. Pulmonary embolism Pulmonary embolism occurs when a blood clot gets lodged in an artery in the lung, blocking blood flow to part of the lung. Blood clots most often originate in the legs and travel up through the right side of the heart and into the lungs.
WordReference Random House Unabridged Dictionary of American English Â© 2016. tread (tred), v., trod, trodâ¢den ortrod, treadâ¢ing, n. v.i. 1  to set down the foot or feet in walking; step; walk.  to step, walk, or trample so as to press, crush, or injure something (usually fol. by on or upon):to tread on a person's foot.
A treadle is a part of a machine which is operated by the foot to produce reciprocating or rotary motion in a machine such as a weaving loom (reciprocating) or grinder (rotary). Treadles can also be used to power water pumps (as in the treadle pump), or to turn wood lathes (as in the pole lathe).