1610s, "to weigh more than," from Latin praeponderatus, past participle of praeponderare "outweigh, make heavier," from prae "before" (see pre-) + ponderare "to weigh," from pondus "weight," from stem of pendere "to hang, cause to hang; weigh" (from PIE root *(s)pen- "to draw, stretch, spin").
Intransitive sense is from 1620s. Meaning "to exceed in force or power" is from 1799. In 17c. English had a verb preponder "outweigh in importance," but it seems not to have survived. Related: Preponderating; preponderation.