Mention report of what was seen (4)
I believe the answer is:
cite
'mention' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for cite that I've seen before include "Quote as evidence" , "Mention as example or quote" , "Summon - quote" , "Quote (an author)" , "Give as an example" .)