Prime student to limit pressure before American exam (6-4)
I believe the answer is:
eleven-plus
'exam' is the definition.
(I've seen this before)
'prime student to limit pressure before american' is the wordplay.
I cannot quite see how this works, but
'prime' could be 'eleven' (eleven is a prime number) and 'eleven' is present in the answer.
'student' could be 'l' (as in L-plates for learner drivers) and 'l' is present in the answer.
'pressure' could be 'p' (abbreviation) and 'p' is found within the answer.
'american' could be 'us' (United States) and 'us' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for eleven-plus that I've seen is " School exam".)