IPA: /ˈweɪstˌpeɪpər/
KK: /ˈweɪstˌpeɪpər/
Paper that has been used and is no longer needed, often thrown away or recycled.
I put the old documents in the wastepaper basket.
Wastepaper is formed from "waste" (from Old French *waste*, meaning to waste or squander) and "paper" (from Latin *papyrus*, meaning a writing material made from the papyrus plant). The word refers to paper that has been used and is no longer needed, hence it is wasted paper.
Think of 'waste' as something that is no longer needed and 'paper' as the material used for writing. This helps you remember that 'wastepaper' refers to paper that is wasted or discarded.