Flirting is a form of human interaction, usually expressing a sexual or romantic interest in the other person. It can consist of conversation, body language, or brief physical contact. It may be one-sided or reciprocated.
Flirting is often used as a means of expressing interest and gauging the other person's interest in courtship, which can continue into long term relationships. Alternatively, it may simply be a prelude to casual sex with no continuing relationship.
In other situations, it may be done simply for immediate entertainment, with no intention of developing any further relationship. This type of flirting sometimes faces disapproval from others, either because it can be misinterpreted as more serious, or it may be viewed as "cheating" if the person is already in a romantic relationship with someone else.
People who flirt may speak and act in a way that suggests greater intimacy than is generally considered appropriate to the relationship (or to the amount of time the two people have known each other), without actually saying or doing anything that breaches any serious social norms. One way they accomplish this is to communicate a sense of playfulness or irony. Double entendres, with one meaning more formally appropriate and another more suggestive, may be used.
There are three degrees of flirting. The first degree is unintentional, and can occur during normal conversations between two people. You are not consciously trying to impress or make the other person laugh, but your subconscious is at work. The second degree is intentionally trying to make the person laugh, or impressing him or her. Lastly, the third degree of flirting is intentional, and not at all subtle. The person is going out of his or her way to impress someone.
Flirting may consist of stylized gestures, language, body language, postures, and physiologic signs, some of which are also part of foreplay. Among these, at least in Western society, are:
Eye contact
"Protean" signals, such as touching one's hair
Casual touches
Smiling suggestively
Winking
Sending and receiving notes, poems, mixtapes, or written music
Saucy teasing
Footsies, the "feet under the table" practice
Giving gifts such as chocolates.
"Flirt fighting" (usually more common with younger people)
Batting eyelashes (in the past done mostly by females, but more recently done by both genders).
The origin of the word flirt is obscure. The Oxford English Dictionary (first edition) associates it with such onomatopoeic words as flit and flick, emphasizing a lack of seriousness; it has also been attributed to the French phrase conter fleurette, which may be loosely translated as "to speak sweet nothings".
http://en.wikipedia.org/wiki/Flirt