Bewhiskered sort of burglar? (3)

I believe the answer is:

cat

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

'sort of burglar?' is the definition.

I don't understand how the remainder of the clue works.

(Other definitions for cat that I've seen before include "Lash < jazz fan" , "Common pet" , "Eg, tiger, lion" , "Animal; converter; boat" , "An old whip with nine tails" .)

I've seen this clue in the Evening Standard.

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