Influence thing done by little devil? (6)
I believe the answer is:
impact
'influence' is the definition.
(I know that influence is a more specific form of the action impact)
'thing done by little devil?' is the wordplay.
'thing done' becomes 'act' (I've seen this in another clue).
'by' is a charade indicator (letters next to each other).
'little devil?' becomes 'imp' (an imp is a little demon).
'act' after 'imp' is 'IMPACT'.
(Other definitions for impact that I've seen before include "Significance" , "Forceful consequence" , "hit, in a big way" , "Repercussions" , "Impression" .)