Study horse’s previous record — and go with the stream (7)
I believe the answer is:
conform
'go with the stream' is the definition.
I can't judge whether this definition defines the answer.
'study horse's previous record' is the wordplay.
'study' becomes 'con' (con can informally mean to study).
'horse's previous record' becomes 'form' (racehorse's past performances).
'con'+'form'='CONFORM'
'and' is the link.
Can you help me to learn more?
(Other definitions for conform that I've seen before include "Keep to rules or general custom" , "Follow the crowd" , "Follow the herd" , "Comply with accepted rules" , "Agree" .)