Gets a dog, one notices, to guard it (7)
I believe the answer is:
secures
'gets a dog' is the definition.
'secures' can be an answer for 'gets' (securing is a kind of getting). I am not sure about the 'a dog' bit.
'one notices to guard it' is the wordplay.
'one notices' becomes 'sees' (I've seen this before).
'to guard' means one lot of letters goes inside another.
'it' becomes 'cur' (I can't justify this - if you can you should give a lot more credence to this answer).
'sees' placed around 'cur' is 'SECURES'.
Can you help me to learn more?
(Other definitions for secures that I've seen before include "Makes firmly attached" , "Ties down" , "Makes safe through rescues" , "Guarantees" , "Closes, fortifies" .)