The only free and comprehensive online etymological dictionary of the Spanish language
mano f. (Noun) "hand"
10th cent. From Latin manus 'id.' From Proto-Italic *man-u- 'id.' From Proto-Indo-European *m̥h2-no- 'id.' From a root *meh2- of uncertain value, but likely connected to waving or summoning.
Indo-European
Romance
Asturian mano, Portuguese mão, Galician man, Catalan , French main, Italian mano, Aromanian mãnã, Romanian mână, Sardinian manu
Italic
Oscan manim "hand," Umbrian manuve "on the hand," South Picene manus "by the hand"
Celtic
Old Irish muin "protection," Middle Welsh mynawc "prince"
Germanic
Old Norse mund "hand," Old High German munt "hand," "protection," Old English mund 'id.'
Hellenic
Ancient Greek μάρη (máre) "hand"