Effect of something little monkey did (6)
I believe the answer is:
impact
'effect' is the definition.
(I know that impact is a type of effect)
'something little monkey did' is the wordplay.
I cannot really see how this works, but
'monkey' could be 'imp' (synonyms) and 'imp' is found within the answer.
The remaining letters 'act' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for impact that I've seen before include "Collision - effect" , "hit, in a big way" , "Significance" , "Repercussion" , "Forceful contact between two objects" .)