Noun (1)

Middle English, going back to Old English cælf, plural calfur (Anglian), cealf (West Saxon), going back to Germanic *kalƀaz, *kalƀiz-, neuter s-stem (whence also Old Saxon kalf "young of a cow," Old High German kalb, Old Norse kalfr, and, from a derivative *kalƀōn-, Old High German kalba "female calf," Gothic kalbo), of uncertain origin

Note: Associated with Greek delphýs "womb," Sanskrit garbha- "womb, fetus," going back to Indo-European *g^welbhu- (see -adelphous), but the expected outcome of an ablaut form *g^wolbh-es- would be Germanic *kwalb-iz-, which does not match the attested forms.

Noun (2)

Middle English, borrowed from Old Norse kalfi "calf of the leg," going back to a Germanic source probably akin to early Modern Dutch kalf "swelling of the hand or foot," Old High German wazzerchalp "edema," German dialect Kalb "muscle"