come off it

Originally a British shortening of "come off the grass!", an older (originally American) phrase. Come off the grass!, which is roughly indicative of the speaker's disbelief, or that the speaker believes that the one being spoken to needs to face reality, is ultimately a play on the oft-seen phrase on signs in places such as public parks: "keep off the grass".

come off it

1. An expression of disbelief.

   Come off it, mate! You can't be serious.

   • 1984 August 18, Gary Ralph, “Meow, Meow”, in Gay Community News, volume 12, number 6, page 5:

     My palace spies have informed my that a certain tacky queen going by the pseudonym "Joey Ganimeed" has been presuming to offer you the 'facts of life' about gay existence (GCN, August 11, 1984). The next time you see him, tell him from me "Come off it, Mary."

   • 2024 March 6, Philip Oltermann, “A feminist? Oh come off it! Why is Netflix idolising a porn star infamous for scenes of violence to women?”, in The Guardian‎, →ISSN:

     A feminist? Oh come off it! Why is Netflix idolising a porn star infamous for scenes of violence to women? [title]

• come on, horsefeathers, pull the other one; see also Thesaurus:bullshit