Mention for top dog (4)

I believe the answer is:

peke

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

'dog' is the definition.
(short for Pekingese)

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

(Other definitions for peke that I've seen before include "5 [MANS BEST FRIEND]" , "Small breed of dog" , "Snub-nosed lap-dog (colloq.)" , "Little dog" , "Breed of dog (shortened)" .)

I've seen this clue in The Sun.

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