a tree that keeps its leaves year-round; an evergreen (as opposed to a deciduous tree).
庭には数本の常緑樹があり、冬でも緑が残る。
There are several evergreen trees in the garden, so it's green even in winter.
公園の植栽計画では、落葉樹と常緑樹を組み合わせて景観を調整する。
In the park's planting plan, deciduous and evergreen trees are combined to balance the scenery.