Kalmar "os trapezoideum" kalma ce ta Latin da ke nufin ƙashi a wuyan hannu, wanda aka sani a Turanci a matsayin "ƙashin trapezoid." Yana ɗaya daga cikin ƙananan ƙasusuwan carpal guda takwas waɗanda ke haɗa haɗin gwiwar hannu. Kashin trapezoid yana a gefen wuyan hannu, tsakanin kasusuwan scaphoid da trapezium, kuma yana bayyana tare da kashi na biyu na metacarpal na hannu.
