Crossword Genius

Surrounded by a certain amount of humidity (3)

Ross

I believe the answer is:

mid

I'm a little stuck... Click here to teach me more about this clue!

'surrounded by a certain amount' is the definition.
I can't tell whether this defines the answer.

'of humidity' is the wordplay.
'of' indicates a hidden word.
'MID' is hidden within 'humidity'.

Can you help me to learn more?

(Other definitions for mid that I've seen before include "Of the central part" , "Dim sort of prefix" , "Denote the centre point" , "Prefix meaning centre" .)

I've seen this clue in The Globe and Mail.
Want a hint initially instead of a full solution? Install my app