Learner facing an exam must be up-to-date (6)
I believe the answer is:
latest
'up-to-date' is the definition.
(thesaurus)
'learner facing an exam' is the wordplay.
'learner' becomes 'l'.
'facing' is a charade indicator (letters next to each other).
'an' becomes 'a'.
'exam' becomes 'test' ('test' can be a synonym of 'exam').
'l'+'a'+'test'='LATEST'
'must be' is the link.
(Other definitions for latest that I've seen before include "Most recent or most tardy" , "Up-to-the-minute" , "Brand new, just out" , "Most recent report" , "style of today" .)