microchimeraWiktionary 原文英美构词拆解micromicro-前缀chimerachimera词干micro-(diminutive) Very small. · (metric units) One millionth.词源说明From micro- + chimera.释义名词noun1(biology) A microchimeric cell2(human biology) A type of human chimera produced when fetal stem cells or maternal cells cross the placenta (fetal-maternal microchimerism) or following blood transfusion (transfusion-associated microchimerism) or organ transplantation.