1560s, from French quintuple (15c.), from Late Latin quintuplex, from Latin quintus "fifth" (related to quinque "five;" from PIE root *penkwe- "five") on model of quadruple. Related: Quintuplicate.
1630s, from quintuple (adj.) or from French quintupler (v.). Related: Quintupled; quintupling.
The population of China quintupled