What does 关键 (guān jiàn) mean in English?

Card 147HSK 2010 Level 4147/586
CARD147
PROGRESS25%
关键
關鍵
guān jiàn
crucial point; crux; CL:個|个[ge4]; key; crucial; pivotal

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