Where does “vaporless” come from?

vaporless (English) comes from English vapor, from Middle English vapour, from Anglo-Norman vapour, from Old French vapor, from Latin vapōr — steam, exhalation, vapour; smoke.

vaporless (English): Without vapor

Definitions

Without vapor

Ancestry of “vaporless”, step by step

vaporless traces back through two separate lines of ancestry.

via English vapor

Step	Language	Word	Meaning
1	English	vapor	Cloudy diffused matter such as mist, steam or...
2	Middle English	vapour	Fumes or vapour; a visible gaseous emission;...
3	Anglo-Norman	vapour	—
4	Old French	vapor	Alternative form of vapeur
5	Latin	vapōr	steam, exhalation, vapour; smoke

via English less

Step	Language	Word	Meaning
1	English	less	To a smaller extent or degree; comparative form...
2	Middle English	les	false; lying; deceptive; falsehood; a lie
3	Old English	lēas	false, lax; false, void, loose; devoid of, loose...
4	Proto-Germanic	*laus	—

Every word from Latin vapōr →Every word from Old French vapor →Every word from Anglo-Norman vapour →