Tends to produce possibly damaging impressions (5)
I believe the answer is:
dents
'damaging impressions' is the definition.
'dents' can be an answer for 'impressions' (dent is a kind of impression). I'm not sure about the 'damaging' bit.
'tends to produce' is the wordplay.
'to produce' is an anagram indicator.
'tends' with letters rearranged gives 'DENTS'.
'possibly' is the link.
Can you help me to learn more?
(Other definitions for dents that I've seen before include "Tends towards small depressions" , "Tends towards small depression" , "Tends to create small depressions" , "reductions in size" .)