Starts to offer advice about five eggs (3)
I believe the answer is:
ova
'eggs' is the definition.
(term for egg cells)
'starts to offer advice about five' is the wordplay.
'starts to' says to take the initial letters.
'about' means one lot of letters goes inside another.
'five' becomes 'V' (Roman numeral).
The initial letters of 'offer advice' is 'oa'.
'oa' placed around 'v' is 'OVA'.
(Other definitions for ova that I've seen before include "Female gametes" , "Eggs; sounds like above" , "Likely end for Russian Fed cup players" , "Female egg cells" , "Multiple Latin eggs" .)