Within context, remember the highest limit (7)
I believe the answer is:
extreme
'limit' is the definition.
(thesaurus)
'within context remember the highest' is the wordplay.
'within' indicates the answer is hidden within the clue.
'EXTREME' can be found hidden inside 'context remember highest'.
(Other definitions for extreme that I've seen before include "Most remote or utmost" , "Draconian" , "Ultimate" , "Most distant" , "sheer" .)