A collectable dog one comes to love (5)
I believe the answer is:
curio
'a collectable' is the definition.
I can't judge whether this definition defines the answer.
'dog one comes to love' is the wordplay.
'dog' becomes 'cur' (both can mean a despicable person).
'one' becomes 'i' (Roman numeral).
'comes to' says to put letters next to each other.
'love' becomes 'o' (love means zero in tennis).
'cur'+'i'+'o'='CURIO'
Can you help me to learn more?
(Other definitions for curio that I've seen before include "Something unusual, perhaps worthy of collecting" , "Unusual object, oddity" , "Interesting object of rarity or difference" , "Intriguing object worth collecting" , "odd thing" .)