Burst forth in another upturn (5)
I believe the answer is:
erupt
'burst forth' is the definition.
(I've seen this in another clue)
'in another upturn' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ERUPT' is hidden in the letters of 'another upturn'.
(Other definitions for erupt that I've seen before include "Break forth" , "Break out like Etna" , "Discharge" , "Suddenly appear" , "Burst forth, like 25" .)