Cat runs, hiding in tree bearing biscuit (7)
I believe the answer is:
oatcake
'biscuit' is the definition.
(I've seen this before)
'cat runs hiding in tree bearing' is the wordplay.
'cat runs' becomes 'atc' (I can't justify this - if you can you should give a lot more credence to this answer).
'hiding in' means one lot of letters goes inside another.
'tree' becomes 'oak' (oak is a type of tree).
'bearing' becomes 'e' (East, a compass bearing or direction).
'atc' put within 'oak' is 'oatcak'.
'oatcak'+'e'='OATCAKE'
Can you help me to learn more?
(Other definitions for oatcake that I've seen before include "Thin biscuit made of ground grain" , "Scots biscuit-like food" , "Traditional Scots biscuit" , "Traditional Scottish biscuit" , "Dry biscuit" .)