also: たかぞら
noun
high altitude; upper air
Refers to the sky or atmosphere at a great height; used in contexts like aviation, meteorology, or describing lofty views.
飛行機は高空を飛んでいる。
The airplane is flying at a high altitude.
高空の気温は地上よりずっと低い。
The temperature at high altitudes is much lower than on the ground.
Compound of 高 (high) and 空 (sky). The reading こうくう is the on'yomi, while たかぞら is a less common kun'yomi reading.