Haha

[Sonia]

Short quick way of letting somebody know you are laughing, most likely at them.

[Rihanna]

The quickest way to pretend that youre interested and also a reason for you to close his or her IM box.

[Britney]

A form of expressing laughter when oral expression is not available, like on the internet.

[Becky]

Ye olde way of saying lol.

[Little_Girl]

A sound made when laughing

[Mark Zuckerberg]

used by nelson in the simpsons in many of circumstances

[Dave Paprocki]

Half Assed [Humor] Attempt

[Julian]

A ditch with a wall on its inner side below ground level, forming a boundary to a park or garden without interrupting the view.