megasigmoidWiktionary 原文英美构词拆解megamega-前缀sigmoidsigmoid词干mega-(originally) Very large, great. · In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by one million (106).词源说明From mega- + sigmoid.释义名词noun1(medicine) Abnormal enlargement of the sigmoid colon.