This is a term that is used when referencing the act of having sex with a woman while she's on her period. Sharks attack women who are menstruating in the ocean, and since you are having sex with a woman's bleeding vagina on the land, it is called 'land sharking'. It can also be called a 'shark attack' and is often accompanied by the Jaws theme song and a hand smacking motion immitating the clamping of sharks' jaws.

This should only be attempted if...
A) one is extremely horny
B) one is extremely commited
C) one is both extremely horny and extremely commited

The office shark is a legendary beast that senselessly attacks office workers, forcing them to go home early. The shark may attack at any time, however the office shark is especially active on Fridays, carrying many a worker off into weekend.

The shark attack is a sexual act in which the woman is standing naked against a wall with ass-cheeks spread. The man then puts his hands above his head as to form a shark fin...then sprints full speed toward the woman yelling "Shark Attack!" and penetrates her without mercy.

Be careful not to break your dick off...I will not be held responsible for any injuries that occur while attempting this risky maneuver.

The wave of mutilation left after having sex while a woman is on her period (shark week). Cleanup can be quite messy.

A Sexual prank where you pool the front of a woman's strapless dress or shirt down, exposing her breasts in the process in front of people. Also known as getting "Sharked".

Man and woman having sex. The woman sits in a folding chair while the man pumps from in front of her. Right before the man finishes he lifts the front of the fold chair up knocking the woman on her back with the folding chair collapsing on her ass like a shark bite!

SHARK ATTACK!
that's the definiton lol idk what else to say
FOR NOOBS:

__ -water
|\ -shark's flipper
\o/ -'\ /' are hands and 'o' is head shouting for help
i've seen it first time while playing hon (heroes of newerth)