Prompt, say, with plague on the rise (5)
I believe the answer is:
nudge
'prompt' is the definition.
(I've seen this before)
'say with plague on the rise' is the wordplay.
'say' becomes 'eg' (both can mean for example).
'with' is a charade indicator (letters next to each other).
'plague' becomes 'dun' (I can't justify this - if you can you should give a lot more credence to this answer).
'on the rise' is a reversal indicator (in a down clue, letters go up).
'eg'+'dun'='egdun'
'egdun' reversed gives 'NUDGE'.
Can you help me to learn more?
(Other definitions for nudge that I've seen before include "Push gently" , "Poke gently with elbow" , "Give a reminder" , "Gentle poke with elbow" , "Encouraging prompt" .)