mwahaha

Denotes evilness. Usually uttered by the very clever while they develop an evil plot. Often accompanied by smirks and sideways glances.

devilishness an evil sound when ur up to something

A common supplement to a comment in internet discussion,used almost exclusively by relatively innocent females; it generally follows a particularly naughty, empowering, or triumphant moment for them in a discussion. Outside of direct discussion (i.e; in a profile, email, etc.), it often follows something entirely random that they said in what they somehow deem to be a very naughty and rebellious overhaul of common sense.
Generally, if you are a male, any use of this directed at you is a good sign; its a flirty, suggestive word choice (similar to the sound of a kiss), and when used with males it almost implies a sort of lustful blushing. It suggests that said female finds you fun, and is comfortable being playful with you.