incline (v.) Look up incline at
in early use also encline, c. 1300, "to bend or bow toward," from Old French encliner "to lean, bend, bow down," from Latin inclinare "to cause to lean; bend, incline, turn, divert," from in- "into, in, on, upon" (see in- (2)) + clinare "to bend," from PIE *klei-n-, suffixed form of *klei- "to lean" (see lean (v.)). Metaphoric sense of "have a mental disposition toward" is early 15c. in English (but existed in classical Latin). Related: Inclined; inclining.
incline (n.) Look up incline at
c. 1600, "mental tendency," from incline (v.). The literal meaning "slant, slope" is attested from 1846 in railroading.