Behold, by study, waterproof cloth (5)

I believe the answer is:

loden

'waterproof cloth' is the definition.
(I've seen this in another clue)

'behold by study' is the wordplay.
'behold' becomes 'lo' (archaic exclamation meaning 'look!').
'by' is a charade indicator (letters next to each other).
'study' becomes 'den' (den can mean an office or study).
'lo'+'den'='LODEN'

(Another definition for loden that I've seen is " Thick, waterproof woollen cloth".)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.