What does 天空 (tiān kōng) mean in English?

Card 956HSK 2010 Level 5956/1311
CARD956
PROGRESS73%
天空
tiān kōng
sky
Click to reveal
← Previous↑ DeckNext →

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