Embryo (4)
'embryo' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for foetus that I've seen before include "Human embryo more than six weeks after conception" , "issue" , "Unborn child" , "Developed embryo in the womb" , "Developed mammalian embryo" .)
'embryo' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for seed that I've seen before include "Court favourite" , "one very much fancied" , "High-rated tennis player" , "who is ranked highly" , "Pip for sowing" .)