Did undergo some enhancement, dropping team of beginners (4,2)
I believe the answer is:
used to
'did' is the definition.
(I've seen this before)
'undergo some enhancement dropping team of beginners' is the wordplay.
'beginners' suggests taking the first letters.
The initial letters of 'undergo some enhancement dropping team of' is 'USED TO'.
(Other definitions for used to that I've seen before include "Accustomed or inured" , "Familiar with" , "Not unfamiliar with" , "Was in the habit" , "Did at times in the past" .)