Little stick, the sort in pool? (7)
I believe the answer is:
tadpole
'sort in pool?' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'little stick' is the wordplay.
'little' becomes 'tad' (both can mean a small amount).
'stick' becomes 'pole'.
'tad'+'pole'='TADPOLE'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for tadpole that I've seen before include "Immature amphibian" , "A frog-to-be" , "Aquatic larva of frog or toad" , "immature sea squirt" , "Immature toad or frog" .)