白天那一段
只看那段光本身：誰在這段時間裡醒著、開著。
adjective · C2
Happening during the daylight hours; or, said of an animal, awake and moving about by day and resting at night; or, said of a flower, open during the day and closed at night.
日行性的、白天的
核心畫面
The stretch of light between sunrise and sunset. Look at that stretch and you can see two things at once: the bright part of the day, and one whole turn of the day that will come round again tomorrow.
可以想成太陽升起到落下的那一段白天。盯著這段光，其實可以看見兩件事：一件是「白天這段時間」，一件是「一天轉完的一圈」…更多收起
可以想成太陽升起到落下的那一段白天。盯著這段光，其實可以看見兩件事：一件是「白天這段時間」，一件是「一天轉完的一圈」。diurnal 的兩個意思就像從這裡往兩邊走——一邊講白天在活動的動物和開著的花，一邊講每二十四小時重來一次的循環。From the word’s history
From Latin diurnalis, from dies (day). Journal comes from the same root, which is why a journal was first a day-by-day record.
來自拉丁文 diurnālis，字根是 diēs（一天、白天）。有趣的是 journal 也是同一條線：journal 一開始就是「每日的記事」。把 diurnal 和 journal 放在一起記，這個「日」的畫面就很好抓。
Wiktionary entry supplied in this batch's evidence packet (source_ref kaikki:3f6f69a190036ae4:282046806): from Latin diurnalis, from dies (day); doublet of journal.
Two branches
一天轉完的一圈
不看光的那一段，改看「這一段走完又重來」的整圈。
adjective · C2
Happening once every day, or going through the same rise and fall over each twenty-four hours, the way the tide, the temperature or the body's own rhythm does.
每日的、以一天為週期的