Ma'anar ƙamus na kalmar "agenesia" ita ce rashi na haihuwa ko gazawar ci gaban wata gaɓa ko nama a cikin jiki. Ana amfani da shi sau da yawa a cikin yanayin likita don yin nuni ga gazawar gabbai ko nama don samar da su yadda ya kamata yayin haɓakar amfrayo, wanda ke haifar da rashinsa a lokacin haihuwa ko kuma daga baya a rayuwa. Agenesia na iya faruwa a wasu gabobin jiki ko nama a cikin jiki, gami da amma ba'a iyakance su ba, hakora, gaɓoɓi, gabobin jiki, da gland.