You keep using that word, followed by I do not think it means what you think it means is a phrase used to highlight someone’s incorrect use of a term.
It was taken from the 1987 comedy The Princess Bride, and is often combined with an image macro of Inigo Montoya, (portrayed by Mandy Patinkin) a character from the movie.
The quote was first shown in the iconic 1987 film The Princess Bride, in which the villain, Vizzini keeps saying the word “Inconceivable!”.
Several exclamations into the movie, Montoya confronts Vizzini (played by Wallace Shawn) with the iconic phrase “You keep using that word, I do not think it means what you think it means”.
The scene was taken out of context and uploaded to YouTube in 2007 and was used in Reddit posts, since 2008.
The meme as an image macro started making appearances on 4chan, Memebase, Tumblr and Reddit following 2010, peaking in 2012.