Belief that goes up and down (5)

I believe the answer is:

tenet

I believe this clue is a double definition.

'belief' is the first definition.
(synonyms)

'that goes up and down' is the second definition.

(Other definitions for tenet that I've seen before include "Article of belief" , "A palindromic doctrine or creed" , "Palindromic principle or belief" , "you may believe in it" , "Doctrine, dogma, belief" .)

I've seen this clue in The Telegraph.

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