sit up and take notice

sit up and take notice (third-person singular simple present sits up and takes notice, present participle sitting up and taking notice, simple past sat up and took notice, past participle sat up and taken notice)

1. To start to pay attention suddenly.
   • 1949 November and December, Cecil J. Allen, “British Locomotive Practice and Performance”, in Railway Magazine, page 365:

     But when we streaked through Doncaster at all but a mile-a-minute, with a miraculously clear road, in no more than 37 min. 18 sec. from the York start, I began to sit up and take notice.

• prick up one's ears

• “sit up and take notice”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.
• “sit up and take notice” (US) / “sit up and take notice” (UK) in Macmillan English Dictionary.
• “sit up and take notice”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.