-blast

1.
variant of blasto- as final element of a compound word:
ectoblast.
British Dictionary definitions for -blast

-blast

combining form
1.
(in biology) indicating an embryonic cell or formative layer: mesoblast
Word Origin
from Greek blastos bud
-blast in Medicine

-blast suff.
An immature, embryonic stage in the development of cells or tissues: erythroblast.