Aide made strange impression (4)
I believe the answer is:
idea
'strange impression' is the definition.
'idea' can be an answer for 'impression' (I've seen this before). I'm not certain of the 'strange' bit.
'aide made' is the wordplay.
'made' indicates an anagram.
'aide' is an anagram of 'IDEA'.
Can you help me to learn more?
(Other definitions for idea that I've seen before include "Product of the mind" , "Notion, concept" , "Notion, image" , "intellectual product" , "Notion, belief" .)