About to include round eggs (3)
I believe the answer is:
roe
'eggs' is the definition.
(I've seen this in other clues)
'about to include round' is the wordplay.
'about' becomes 're' (regarding**).
'to include' indicates putting letters inside.
'round' becomes 'o' (round can mean a round object).
're' placed around 'o' is 'ROE'.
(Other definitions for roe that I've seen before include "Food from fish" , "Mass of fish's eggs" , "A mass of fish-eggs" , "eg Caviare" , "shy animal" .)