Peer round inside capsized slaver (5)

I believe the answer is:

drool

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

'slaver' is the definition.
(I know that slaver can be written as drool)

I can't explain the rest of the clue.

(Other definitions for drool that I've seen before include "Salivate" , "Let saliva run from the mouth" , "dribble" , "Slobber" , "Slaver - drivel" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app