Make evident (6)
'make evident' is the definition.
(synonyms)
This is all the clue.
(Other definitions for attest that I've seen before include "Give sworn evidence" , "Give testimony in a court of law" , "say, in court" , "Bear formal witness to, give evidence" , "University town" .)
'make evident' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for evince that I've seen before include "Give expression to" , "Venice (anag.)" , "Express,show" , "Show or reveal, say interest" , "Indicate, show clearly" .)