Impact he made in strong terms (8)
I believe the answer is:
emphatic
'strong terms' is the definition.
The answer and definition are not the same part of speech.
'impact he made' is the wordplay.
'made' is an anagram indicator.
'impact'+'he'='impacthe'
'impacthe' with letters rearranged gives 'EMPHATIC'.
'in' is the link.
Can you help me to learn more?
(Other definitions for emphatic that I've seen before include "Categorical" , "Forceful - pronounced" , "In no uncertain terms" , "Impact he combined with special stress" , "being stressed" .)