How do you spell Hannukah?
1885, medical Latin, from Greek a-, privative prefix (see a- (3)), + -plasia.
aplasia a·pla·si·a (ə-plā'zē-ə, -zhə)n.
Congenital absence of an organ or tissue.
Incomplete, retarded, or defective development of an organ or tissue.
Cessation of the usual regenerative process in an organ or tissue.