废材 originally meant 'scrap material' (
废 waste +
材 material), and is now a popular slang insult borrowed from Cantonese
廢柴 (fai³ caai⁴). It's a staple of internet novels (
网文) and
玄幻 fantasy fiction, where the trope 'loser-turned-prodigy' is so common it has its own genre tag:
废材逆袭. Self-deprecating use among friends is mild; calling someone else
废材 is genuinely insulting.
