Signal that may prompt a rising (5,4)
I believe the answer is:
alarm bell
'signal that may prompt a rising' is the definition.
'alarm bell' can be an answer for 'signal' (alarm bell is a kind of signal). I am unsure of the rest of the definition.
'signal that may prompt' is the wordplay.
'signal' becomes 'alarm' (alarm is a kind of signal).
'that may prompt' becomes 'bell' (I can't explain this - if you can you should believe this answer much more).
'alarm'+'bell'='ALARM-BELL'
Can you help me to learn more?
(Other definitions for alarm bell that I've seen before include "Warning signal" , "Ring it to signal danger" , "Warning device" , "Warning sound" , "It rings as a warning" .)