Acceptable video about a learner (5)
I believe the answer is:
valid
'acceptable' is the definition.
(thesaurus)
'video about a learner' is the wordplay.
'video' becomes 'vid'.
'about' means one lot of letters goes inside another.
'learner' becomes 'l'.
'a'+'l'='al'
'vid' enclosing 'al' is 'VALID'.
(Other definitions for valid that I've seen before include "Legally acceptable, unexpired" , "Reasonable" , "Sound, well-based" , "Well-grounded" , "Still legally acceptable" .)