Taken from the Online Etymology Diction
govern (v.)
late 13c., from O.Fr. governer (11c., Mod.Fr. gouverner) "govern," from L. gubernare "to direct, rule, guide, govern" (cf. Sp. gobernar, It. governare), originally "to steer," a nautical borrowing from Gk. kybernan "to steer or pilot a ship, direct" (the root of cybernetics). The -k- to -g- sound shift is perhaps via the medium of Etruscan. Related: Governed; governing.
mentation (n.)
"mental function," 1850, from L. ment- "mind" (see mental) + -ation.
govern (v.)
late 13c., from O.Fr. governer (11c., Mod.Fr. gouverner) "govern," from L. gubernare "to direct, rule, guide, govern" (cf. Sp. gobernar, It. governare), originally "to steer," a nautical borrowing from Gk. kybernan "to steer or pilot a ship, direct" (the root of cybernetics). The -k- to -g- sound shift is perhaps via the medium of Etruscan. Related: Governed; governing.
mentation (n.)
"mental function," 1850, from L. ment- "mind" (see mental) + -ation.