Reversible zip (3)

I believe the answer is:

pep

I believe this clue is a double definition.

'reversible' is the first definition.

'zip' is the second definition.
(I've seen this before)

(Other definitions for pep that I've seen before include "Palindromic energy or vim" , "savings plan" , "Energy, zip" , "Go" , "Palindrome for vigour" .)

I've seen this clue in The Telegraph.

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