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outside; exterior
the open (air)
other place; somewhere else; outside one's group (family, company, etc.)
「外」 has other readings with different meanings.
今日は外がとても寒いよ。
It's very cold outside today.
子どもたちが外で遊んでいる。
The children are playing outside.
外に出たら気持ちのいい風が吹いていた。
When I went outside, a pleasant breeze was blowing.