four o'clock

Questions about four o'clock

What does four o'clock mean?

four o'clock means "any of several plants of the genus Mirabilis having flowers that open in late afternoon".

Is four o'clock a common word?

four o'clock is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.