Gosh how it goes up and down! (3)
I believe the answer is:
wow
This clue could be a double definition.
'gosh' is the first definition.
'up and down' is the second definition.
'how it goes' is the link.
This may not be correct. Some or all of it may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for wow that I've seen before include "Expression of amazement" , "Palindrome exclamation of astonishment or admiration" , "Great success" , "Expression of surprised admiration" , "Exclamation of admiration - another palindrome" .)