What does 扩建 (kuòjiàn) mean in English?

Card 1531HSK Level 41531/3571
CARD1531
PROGRESS43%
扩建
擴建
kuòjiàn
extend; expand(Verb)

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