Small seal called out for young creature in river (6)
I believe the answer is:
cygnet
'young creature in river' is the definition.
I can't tell whether this definition defines the answer.
'small seal called out' is the wordplay.
'small seal' becomes 'signet' (type of official seal).
'called out' shows a homophone (sound like).
'signet' is a homophone of 'CYGNET'.
'for' is the link.
Can you help me to learn more?
(Other definitions for cygnet that I've seen before include "Small pen, perhaps?" , "Youthful swan" , "small pen? Possibly" , "Young aquatic bird" , "Young water bird" .)