1) A Crazy Person (Derived from police code)

2) A Hooligan
Requesting backup, there is a 45 at the playground threatening people

Look at that 45 vapeing over there
by Szechuan October 12, 2017
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A phonograph record played at 45 RPM. It was about 8 inches across and had a very large central hole. It played a single song.
Peggy Sue has a whole box of Elvis 45s.
by Cap'n Bullmoose April 23, 2005
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A hybrid left hook/uppercut, coined by Oscar De La Hoya due to the angle at which the punch is delivered.
“I just reached for my '45' and just like the Carter fight," De La Hoya delivered a “skin-shattering cut, this time over the left eye of my opponent."
by ChippL December 28, 2008
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A 45 pound (20kg) standard weight plate used on Olympic barbells. Often referred to simply as "1 plate" or "a plate".
I hit a new personal best on deadlift yesterday repping three 45's. That's 160kg, not counting the bar!
by knikknax September 06, 2015
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Explosive, foul, vile, odious bowel movement
I just had to take a #45 . Do NOT go into the bathroom!
by PorFin April 11, 2018
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1. The number that is after 44 and before 46

2. A Colt 1911 .45ACP. Despite only holding 7 or 8 rds, the 45 is like twice as powerful as a 9mm, even if the bullet is slower. Usually a term only given to a colt because most other .45ACP guns look like 9mms at a glance
Dude: Im gonna put a 45 in that asshole if he dont watch
by carlbittner October 25, 2008
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She was 45ed by her own brother and lost her clearance and her house.
by LanceHN August 12, 2019
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