Objections from experts covering trial (8)
I believe the answer is:
protests
'objections' is the definition.
(protest is a kind of objection)
'experts covering trial' is the wordplay.
'experts' becomes 'pros' (I've seen this in other clues).
'covering' indicates putting letters inside.
'trial' becomes 'test' ('test' can be a synonym of 'trial').
'pros' enclosing 'test' is 'PROTESTS'.
'from' is the link.
(Other definitions for protests that I've seen before include "Expresses an objection" , "Public demonstrations to object to something" , "Complaints and objections" , "Raises objection" .)