look up any word, like fleek:
 
2.
The number of people that one has had sex with.
My magic number was eight before Spring Break. I broke double digits before coming back home.
by Mike January 06, 2005
 
1.
A constant compiled into a computer program or used in a file format for the purpose of being identifiably unique. A number which could only exist in memory on purpose and rarely by accident. For example, 0 is a bad choice for a magic number, since it's the default value for memory when a computer is turned on.

Programmers use them to quickly validate a larger data structure which could crash if it guesses the type wrong, using the theory that whatever code put the magic number there probably got the rest of it right, since they would have made it store the magic number AFTER everything else checked out.

Usually it's something easy for a programmer to remember, like DEADBEEF or B00B135 or something equally assinine.

It's like a secret signal or whistle you might use with friends when trying to coordinate something sneaky.
I fed an mp3 I accidentally renamed to a avi into windows media player, but it didn't crash because it checked the magic number first.
by pr0ntab January 08, 2004
 
3.
1. A score of 69 or a run of 69 consecutive points in straight pool.

2. The 6-9 combination in pool, especially 9 ball.

3. 69 (the sexual act).
1. Wow! She won the match 100-73 and had advanced to the finals. No one thought she'd pull it off when she was down 73-31. She performed the magic number---69 and out! One hell of a run!!!

2. Look! All I have to do is hit the magic number and I win this rack. The 6-9 combination--ooh, la la, so soon!

No wonder those two are so quiet: they must be performing the magic number on each other
by meow2u3 August 15, 2010
 
4.
A guy's "magic number" is the number of inches his penis is. IT SHOULD BE MEASURED IN WHOLE INCHES, OR HALF INCH INCREMENTS. No 3/4 shit.
I just found out my boyfriend's magic number! But dude, he was a douche and said 7 and 3/4 inches!
by tehhottlemon November 09, 2005
 
5.
1. A score of 69 in sports.

2. The 6-9 combination in pool, particularly 9-ball.

3. 69
1. What's the score?
I got the magic number

2. One way to win the rack: the magic number. The 9 is hanging in the pocket.
by Stop the pendulum January 08, 2006