(informal)ensure that all details are correct
(非正式)一丝不苟，重视细节
(informal)exactly on time
(非正式)准时地
he arrived on the dot at nine o'clock.
他准时在九点整到达。
(Brit. informal)a very long time ago
(英，非正式)很久以前
that wallpaper has been there since the year dot.
墙纸是很久以前贴的。
Exactly at the appointed time; punctual or punctually
准时：正好在指定时间的；准时的或准时地
arrived at nine o'clock on the dot.
于九点准时到达