555 Timer is an integrated circuit (chip) which is broadly used in electronics. Its use cases range from Square wave generation to some sort of analog to digital conversion. It can be found at electronics since several decades ago.

Pronounced as Five-Five-Five Timer.
555 Timer can do what an electronics nerd wants to do, Square, Sine, Triangle, you name it.
by alienozi February 26, 2018
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The universal phone number used in examples, so as to imply that it is not a real number. It is almost entirely understood that the number is not to be called, as it is "not a real phone number" If it is a real number, I feel bad for the guy who has it.
"hey dude text me at 555-5555"
by yay balloons! December 14, 2009
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555'ed - to be 555'ed - to be given a false telephone number by an attractive member of the opposite sex.

telephone numbers beginning in 555 are used exclusively in movies and are not real numbers.

A 555 number is usually given to avoid embarassment on the part of the person asked, but it is also a dismissive gesture that can be embarassing when the person who asked for the number finds out what has happened; however, since the 555 number has its origins in film, recipients of the number may feel they have been turned down in a "glamorous" way, which softens the blow.
Hey can I have your number?

...Sure! Here it is. Bye!

Aw, dude, she 555'ed you!

What?

Look at the number - 555 - 0001. You got 555'ed - it's fake!
Man that really sucks, she was awfully cute.

No, she was hot, way out of your league, but now you have a funny story!

Yeah...I guess.
by mattslion123 January 19, 2011
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a link pointing to page that is 404 (not found) or a page which is not what it is supposed to be.
i was warezing the other day and every link i clicked was 555; no software, all pr0n and penis enlargments.

wikileaks posted a link to some damning scandal pictures but by the time i read the page all the links were 555.

rick rolling

this example has to include 555 link (even though 'link' is implicit). : )
by turbandic October 30, 2011
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Mysterious legend in a small upstate New York town called Lake George. Known for multiple female inquiries as well as his big bulge in his tight Connecticut Pants.
Oh my!!!! Do you see that hunk over there? That must be that Darkside-555 guy!!!!
by Cuzzymike January 20, 2021
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Another form of saying, "On My Way" or "On the Way". It is originally from Starcraft when the player issues a move command to the Valkyrie unit and the unit says, "In the pipe, 555".
Kid 1: When you coming over?
Kid 2: 555
Kid 1: Iight, I'll meet you in front
by Korea419 May 8, 2012
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if a new species of animal has lived on earth for more than two minutes, then Chuck Norris has killed it... twice.
Scientist: Hey Chuck look at this new type of spider!

Chuck Norris: Rule 555

Scientist: Damn you Chuck!!!
by Chuck's stunt double October 3, 2010
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