Losing day, postpone returning from college (4)
I believe the answer is:
yale
'college' is the definition.
'losing day postpone returning' is the wordplay.
'losing' suggests deleting specific letters.
'day' becomes 'd'.
'postpone' becomes 'delay' (I've seen this before).
'returning' says the letters should be written in reverse.
'delay' with 'd' removed is 'elay'.
'elay' backwards is 'YALE'.
'from' acts as a link.
(Other definitions for yale that I've seen before include "security device" , "University in USA" , "member of College League" , "US university; lock" , "Famous American university in Connecticut" .)