multiply
v.
mid-12c., multeplier, "to cause to become many," from Old French multiplier, mouteplier (12c.) "increase, get bigger; flourish; breed; extend, enrich," from Latin multiplicare "to increase," from multiplex (genitive multiplicis) "having many folds, many times as great in number," from comb. form of multus (see multi-) + -plex "-fold," from PIE *plek- "to plait" (see ply (v.1.)). Mathematical sense is attested from late 14c. Related: Multiplied; multiplying.
〔李〕[multi-=many times 多次；ply=to fold 对折 ⇒“to fold many times 对折多次”⇒“to increase in number增加”→] v. ①increase 增加
〔李〕[multi=many多；ply=to fold折→“to fold many times折叠多次”→] v. ① (cause) to grow in number（使）增加