adv

• (figurative) In a very short (but unspecified) amount of time.
  "The change seemed to happen overnight."

verb

• (intransitive) To stay overnight; to spend the night.
  "His visits to Paris (which he had not allowed his son to visit until he was a teenager) became less frequent too: he never over-nighted there, for example, after 1744."
• (transitive, US) To send something for delivery the next day.
  "We can overnight you the documents for signature."

noun

• (television, in the plural) Viewership ratings for a television show that are published the morning after it is broadcast, and may be revised later on.
  "Word spread that Barney was on his way out to the location and that the Nielsen overnights had been terrific, or why else would he come."
• (obsolete) The fore part of the previous night; yesterday evening.
  "Pardon me, madam: If I had given you this at overnight, She might have been o'erta'en"