With one being admitted, pause exam (5)
I believe the answer is:
resit
'exam' is the definition.
(as in resitting an exam)
'with one being admitted pause' is the wordplay.
'with one' becomes 'i' (Roman numeral. I am not sure about the 'with' bit.).
'being admitted' is an insertion indicator (inserted letters are admitted in).
'pause' becomes 'rest' (resting is a kind of pausing).
'i' going into 'rest' is 'RESIT'.
Can you help me to learn more?
(Other definitions for resit that I've seen before include "second try at test" , "tested again" , "Take examination again" , "Retake exam" , "Repeat (an exam)" .)