Crossword Genius

Formally confirm Top comeback for one-time circus performer (3,4)

Ross

I believe the answer is:

sea lion

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

'circus performer' is the definition.
(I've seen this in another clue)

'formally confirm top comeback' is the wordplay.
'formally confirm' becomes 'seal' (I've seen this in another clue. I am not sure about the 'formally' bit.).
'top' becomes 'noi' (resembles No s).
'comeback' is a reversal indicator.
'noi' in reverse letter order is 'ion'.
'seal'+'ion'='SEA-LION'

'for one-time' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.

Can you help me to learn more?

(Other definitions for sea lion that I've seen before include "Large marine mammal" , "Large seal" , "Marine animal, used as a circus performer" , "Large-eared mammal of Pacific Ocean, like Leo" , "Creature" .)

I've seen this clue in The Independent.
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.