any device that indicates the humidity of the air without necessarily measuring it
WordReference Random House Unabridged Dictionary of American English © 2026
hy•gro•scope
(hī′grə skōp′),USA pronunciation n.
- Meteorologyan instrument that indicates the approximate humidity of the air.
- hygro- + -scope 1655–65
Collins Concise English Dictionary © HarperCollins Publishers::
'hygroscope' also found in these entries (note: many are not synonyms or translations):