 It was common for mid @-@ sixteenth century Tuscan families to name the eldest son after the parents ' surname - hence , Galileo Galilei was not necessarily named after his ancestor Galileo Bonaiuti . The Italian male given name " Galileo " ( and thence the surname " Galilei " ) derives from the Latin " Galilaeus " , meaning " of Galilee " , a biblically significant region in Northern Israel . 
