Hunting relations left at sea (5,5)
I believe the answer is:
blood sport
'hunting relations' is the definition.
The definition suggests a singular noun which matches the answer.
'left at sea' is the wordplay.
'left' becomes 'port' (left side of a ship - opposite of starboard).
'at' means one lot of letters go next to another (I've seen this in other clues).
'sea' becomes 'bloods' (I can't justify this - if you can you should believe this answer much more).
'port' put after 'bloods' is 'BLOOD SPORT'.
Can you help me to learn more?
(Other definitions for blood sport that I've seen before include "deadly pursuit" , "In the chase" .)