複数【ふくすう】
plural, multiple, several
複雑【ふくざつ】
complex, complicated, intricate, mixed (feelings)
複合【ふくごう】
composite, combined, complex
重複【ちょうふく】
duplication, repetition, overlapping, redundancy, restoration
複製【ふくせい】
reproduction, duplication, reprinting
複写【ふくしゃ】
copying, duplication, reproduction, copy