Those are secondary meanings which make perfect sense, compare that with the Latin for “breath” which has given us aspiration/آرزو, spirit/روان as well as many other secondary meanings.But دم also means ‘stuffy air’, ‘heat’.
I would also say yes. The act of breathing دمیدن or دم زدن as we all know consists of inhalation and exhalation which takes a very small amount of time. Before the age of atomic clocks, for us human being the smallest space of time was a "moment" and the Persian speaking peoples gave this span the name "دم". This span of breath not only was given a time frame but also a space frame. This space is so small that the width of a sword blade or its edge became known as دمِ شمشیر. When one is at a very short space away from someone's door, one is at its threshold or دمِ در. So, you can see how time and space are interlinked almost as if Einstein himself had been a Persian speaker!
As a native speaker when I read دم در/dame dar, just now, ‘door’s breath’ came to my mind, maybe دم here refers to air that flows through gaps of a door, literally one’s so close to the door that one feels the subtle draught around it, its breath.When one is at a very short space away from someone's door, one is at its threshold or دمِ در.
I suppose this can have more than one meaning: 1) the steam or heat/دم produced when a sword is dipped in water during its manufacture, 2) the draught/rush of air (breath) produced by a sword when it is swung in an attempt to kill someone, and I suppose having felt دمِ شمشیر and lived to tell the tale is taken as being extremely lucky, otherwise دمِ شمشیر means certain/imminent death.This space is so small that the width of a sword blade or its edge became known as دمِ شمشیر
This one is interesting, here دم has taken on the meaning of ‘the cutting edge of sword’s blade’ which is not the same as other meanings we know of دم, any thoughts?(کنایه از آبداری و تیزی تیغ ودهن تیغ و روی تیغ تیز گویند و با ریختن و برگشتن مستعمل است. (از آنندراج -||
مکش تیغ زبان صائب به هر بیهوده گفتاری
که از عاجزکشیها این دم شمشیر می ریزد.