An arrest on cattle property in river offshoot (9)
I believe the answer is:
anabranch
'river offshoot' is the definition.
The definition suggests a singular noun which matches the answer.
'an arrest on cattle property in' is the wordplay.
'arrest' becomes 'nab' (synonyms).
'on' means one lot of letters goes inside another.
'cattle property' becomes 'arch' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' is an insertion indicator.
'nab' going within 'arch' is 'anabrch'.
'an' put within 'anabrch' is 'ANABRANCH'.
Can you help me to learn more?
(Another definition for anabranch that I've seen is " Stream".)