the use of boss for cow or calf in English probably goes back to the Ancient Greek bous for ox

Latin bōs, bovis, Classical Greek βους (bous, /'bo:s/) (Modern Greek βους (bous, /'vus/)), English cow, kine, Old English cy, Sanskrit go (gaus) 'ox' are all from PIE *gwou- 'ox, bull, cow'.

English boss is usually thought to be from Latin bōs. Note that the phonologies of Classical and Modern Greek are different.

Ceci n'est pas un seing.