inclination (n.)

"condition of being mentally disposed" (to do something), late 14c., from Middle French inclination (14c.) and directly from Latin inclinationem (nominative inclinatio) "a leaning, bending," figuratively "tendency, bias, favor," noun of action from past participle stem of inclinare "to bend, turn; cause to lean" (see incline (v.)). Meaning "action of bending toward" (something) is from early 15c. That of "amount of a slope" is from 1799.