What's the difference between "vapour" and "mist"?
I ask because I was reading the Wikipedia article for Electronic Cigarettes and there is a lengthy and acrimonious discussion. I don't want to get involved! But I do want to know if there is a difference, and what it is.
Best Answer
Historically, mist was categorized as a meteorological or atmospheric condition. Hence, Webster's Dictionary of Synonyms (1942) lists mist in a category with haze, fog, smog, and brume:
Figuratively, as Merriam-Webster's Eleventh Collegiate Dictionary (2003) observes, mist can also refer to various things suggestive of atmospheric mist:
In contrast, though vapor can be used to describe mistlike conditions, it has a stronger connection to gaseous rather than particulate solid or liquid states. It comes from the Latin word vapor meaning steam. Again from the Eleventh Collegiate, here are the first three definitions:
Given the association of vapor with heating or sublimating into lighter than air gases (and leaving aside the stubborn fact that vapor has long been used as a way to describe fogs and—inevitably—mists), one might argue that a vapor in many instances rises, while a mist tends to descend slowly.
Incidentally, Noah Webster, in his Compendious Dictionary of the English Language (1806) gives only the heated or sublimated sense of vapor:
Samuel Johnson, Dictionary of the English Language (1756) has a more varied (and interesting) take on the word: