depend (v.)

mid-15c., "to be attached to as a condition or cause, be a conditional effect or result," a figurative use, also literal, "to hang, be sustained by being attached to something above;" from Old French dependre, literally "to hang from, hang down," and directly from Latin dependere "to hang from, hang down; be dependent on, be derived," from de "from, down" (see de-) + pendere "to hang, cause to hang; weigh" (from PIE root *(s)pen- "to draw, stretch, spin").

From c. 1500 as "to rely, rest in full confidence or belief;" from 1540s as "be sustained by, be dependent (on)." Related: Depended; depending.