Cells seen as round with very small area (3)
I believe the answer is:
ova
'cells' is the definition.
(ovum is a kind of cell)
'round with very small area' is the wordplay.
'round' becomes 'o' (round can mean a round object**).
'with' says to put letters next to each other.
'very' becomes 'v' (abbreviation).
'small area' becomes 'a' (abbreviation for area often seen in geometry).
'o'+'v'+'a'='OVA'
'seen as' is the link.
(Other definitions for ova that I've seen before include "Female egg-cells" , "Female reproductive cells" , "Eggs; sounds like above" , "Likely end for Russian Fed cup players" , "Latin egg-cells" .)