A record number of contestants in the field (5)
I believe the answer is:
entry
This could be a double definition.
'a record' is the first definition.
(eg entry in a list)
'number of contestants in the field' is the second definition.
'entry' can be an answer for 'field' (I've seen this before). I am not sure about the 'number of contestants in the' bit.
Can you help me to learn more?
(Other definitions for entry that I've seen before include "Admission" , "Competitor" , "Lobby" , "Record - number of contestants" , "List of competitors" .)