Rise while cold and then stop (6)
I believe the answer is:
ascend
'rise' is the definition.
(I know that ascend is a more specific form of rise)
'while cold and then stop' is the wordplay.
'while' becomes 'as' (eg 'while I walked' means 'as I walked').
'cold' becomes 'C' (eg on taps).
'and then' means one lot of letters go next to another (I've seen this in other clues).
'stop' becomes 'end' (synonyms).
'as'+'c'+'end'='ASCEND'
(Other definitions for ascend that I've seen before include "Gain height" , "rise in status" , "Move upward" , "Soar" , "Make the top" .)