vaporous

UK: /ˈveɪpərəs/ US: /ˈveɪpərəs/ ,(vā′pər əs)

WordReference Random House Learner's Dictionary of American English © 2025

va•por•ous /ˈveɪpərəs/   adj. 

1. Meteorology having the form of vapor;
   full of vapor;
   foggy:
   a vaporous cloud; vaporous bogs.
2. vaguely formed;
   not clearly defined;
   not substantial:
   vaporous arguments that make no sense.

WordReference Random House Unabridged Dictionary of American English © 2025

va•por•ous  (vā′pər əs), adj. 

1. Meteorology having the form or characteristics of vapor:
   a vaporous cloud.
2. Meteorology full of or abounding in vapor; foggy;
   misty:
   a vaporous twilight.
3. producing or giving off vapor:
   a vaporous bog.
4. dimmed or obscured with vapor:
   a low valley surrounded by vaporous mountains.
5. unsubstantial;
   diaphanous;
   airy:
   vaporous fabrics; vaporous breezes.
6. vaguely formed, fanciful, or unreliable:
   vaporous promises.

• vapor + -ous 1520–30

va′por•ous•ly, adv. 
va′por•ous•ness, va•por•os•i•ty  (vā′pə ros′i tē), n. 

Collins Concise English Dictionary © HarperCollins Publishers::

vaporous / ˈveɪpərəs/ adjective

1. resembling or full of vapour
2. another word for vaporific
3. lacking permanence or substance; ephemeral or fanciful
4. given to foolish imaginings

ˈvaporously adverb

ˈvaporousness, vaporosity / ˌveɪpəˈrɒsɪtɪ/ noun