Frogs' eggs (5)
I believe the answer is:
spawn
'frogs' eggs' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for spawn that I've seen before include "Eggs of fish, frogs, etc" , "(Of fish) release eggs" , "Produce" , "Eggs deposited by fish" , "Eggs deposited by amphibians" .)