— heterochronic /het'euhr euh kron"ik/ , heterochronistic, heterochronous , adj.
/het'euh rok"reuh nee/ , n. Biol.
a genetic shift in timing of the development of a tissue or anatomical part, or in the onset of a physiological process, relative to an ancestor.
[ 1875-80; HETERO- + CHRON- + -Y 3 ; cf. G Heterochron ]