Scary exclamation about louse egg and fish (6)
I believe the answer is:
bonito
'fish' is the definition.
(bonito is a kind of fish)
'scary exclamation about louse egg' is the wordplay.
'scary exclamation' becomes 'boo' (I have seen 'Exclamation of disapproval ' mean 'boo' so perhaps 'exclamation' could also mean 'boo'. I am not sure about the 'scary' bit.).
'about' indicates putting letters inside.
'louse egg' becomes 'nit' (I've seen this before).
'boo' placed around 'nit' is 'BONITO'.
'and' is the link.
Can you help me to learn more?
(Another definition for bonito that I've seen is " Fish".)