up to something

• (Received Pronunciation) IPA^(key): /ˈʌp tuː ˈsʌmθɪŋ/
• (General American) IPA^(key): /ˈʌp tə ˈsʌmθɪŋ/

• Audio (General Australian):

  (file)

• Hyphenation: up to some‧thing

up to something (not comparable)

1. (idiomatic) Doing something mischievous or scheming.

   He looks like an angel, but I can tell he's up to something.

   • 1871 October 27, Prince McElhannon (witness), “The Ku-Klux Conspiracy”, in Testimony Taken by the Joint Select Committee to Inquire into the Condition of Affairs in the Late Insurrectionary States. Georgia, volume II, Washington, D.C.: Government Printing Office, published 1872, →OCLC, page 649:

     I took my mare and went down to the swamp, for I knew they had been up to something there from the signs I saw.

   • 1922 February, L. B. Thoburn-Clarke, “Amid the Swamps. A True Story of New Zealand Life in the Early Days.”, in The Boy's Own Paper, volume XXXVIII, part 4, London: "Boy's Own Paper" Office, , →OCLC, section II, page 212, column 2:

     One or another of them will be poking their heads in and see we have been up to something [...]

   • 1955 January 22, S. Roberts, “The Man who Made the Grade: A Short Story”, in Ram Singh, A. K. Mukerji, editors, Thought, air edition, volume VII, number 4, New Delhi: Printed on behalf of Siddhartha Publications Ltd., by R. L. Chadha at Naya Hindustan Press, →ISSN, →OCLC, page 10, column 1:

     One day Chander, who was always up to something, took it into his head to ring up one or two customers in regard to bills long outstanding on them.

   • 2005 August 25, Simon Cox, “A 'Neet' Solution”, in BBC News‎, archived from the original on 8 July 2018:

     If they are doing nothing they are going to be up to something – just send them to prison.

   • 2010, BioWare, Mass Effect 2 (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC:

     Shepard: Last I knew, Kaidan was Alliance. Why is he out in the Terminus Systems?
     Illusive Man: Officially, it's an outreach program to improve Alliance relations with the colonies.
     Illusive Man: But they're up to something. And if they sent Commander Alenko, it must be big.

   • 2003 December 13, “Crime scene”, in The Age‎, Melbourne, Vic.: Nine Publishing, →ISSN, →OCLC, archived from the original on 18 September 2018:

     Police knew who they were. They knew they were up to something. All they could do was wait.

   • For more quotations using this term, see Citations:up to something.

• up to no good
• be up to

• “up to something”, in OneLook Dictionary Search.