What does 金属 (jīn shǔ) mean in English?

Card 521HSK 2010 Level 5521/1311
CARD521
PROGRESS40%
金属
屬属
jīn shǔ
metal; CL:種|种[zhong3]

Reveal: Click/Space/Enter/↑↓/w/s/j/kNavigate: ←→/h/l/a/d