aplasia a·pla·si·a (ə-plā'zē-ə, -zhə)
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.
aplastic a·plas·tic (ā-plās'tĭk, ə-plās'-)
Unable to form or regenerate tissue.
Of, relating to, or characterized by aplasia.