Sound choice of toy for someone very young (6)
I believe the answer is:
rattle
'sound' is the definition.
(I know that rattle is a more specific form of sound)
'choice of toy for someone very young' is the wordplay.
I cannot quite understand how this works, but
'someone' could be 'rat' (rat is a kind of someone) and 'rat' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for rattle that I've seen before include "Make worried, baby's toy" , "Child's toy or kind of snake" , "American viper" , "Venomous creature's warning" , "American snake" .)