1) the liver

1a) the liver (as the heaviest organ)

Root √כבד: כָּבֵד vb be heavy weighty burdensome honoured Qal be heavy , in weight heavy insensible dull . be honoured Niph be made heavy fr. abundance be honoured enjoy honour . of man pass. get oneself glory honour medial,(or), of God . Pi make heavy insensible , make honourable honour glorify . usu. c. human subj. . Pu be made honourable honoured . Hiph make heavy make heavy dull unresponsive . the ears cause to be honoured . Hithp make oneself heavy dense numerous . honour oneself .

כָּבֵד n.m La 2:11 liver heavy par excellence .(explained by Thes (quoting Galen) as theorgan. of the body)