A song by Guns N' Roses on their debut album, Appetite for Destruction. Essentially, it's about one's initial introduction to the seedy underworld of America.

It also serves as a nice pump-you-up song.

A kick ass song. Theme song to San Andreas.

Being completely unprepared for a situation and making it very apparent you are neither prepared nor capable of functioning in a particular capacity

Once a Guns N' Roses song, this term may now refer to the monstrosity known as an unshaved/untrimmed pubic area. Few who enter the confines of such a beastly jungle ever return to tell about it.

when a girl sees your dick for the first time and it is really hairy, you say "welcome to the jungle."

An invitation to groom or admire one's pubic hair. Originally from a Guns 'N Roses song, however, Mountain Pointe High School turned the phrase into a travesty. It is now the butt of all jokes among students in the yearbook class. Not really. It actually has everything to do with anal sex, ever.

The song Master Wu play on his staff

Oh my god
Jump
Welcome to the jungle, we've got fun and games
We got everything you want honey, we know the names
We are the people that can find whatever you may need
If you got the money, honey, we got your disease
In the jungle, welcome to the jungle
Watch it bring you to your sha-n-n-n-n-n-n-n-n knees, knees
Mwah, I, I wanna watch you bleed
Welcome to the jungle, we take it day by day
If you want it you're gonna bleed but it's the price to pay
And you're a very sexy girl who's very hard to please
You can taste the bright lights but you won't get there for free
In the jungle, welcome to the jungle
Feel my, my, my, my serpentine
Ooh, ah, I want to hear you scream
Welcome to the jungle, it gets worse here every day
You learn to live like an animal in the jungle where we play
If you got a hunger for what you see you'll take it eventually
You can have anything you want but you better not take it from me
In the jungle, welcome to the jungle
Watch it bring you to your sha-n-n-n-n-n-n-n-n-knees, knees
Mwah, I'm gonna watch you bleed
And when you're high, you never ever wanna come down
So down, so down, so down, yeah
You know where you are?
You're in the jungle, baby, you're gonna die
In the jungle, welcome to the jungle
Watch it bring you to your sha-n-n-n-n-n-n-n-n-knees, knees
In the jungle, welcome to the jungle
Feel my, my, my my, serpentine