A hug betewwn two men that lasts no more that 5 seconds and as you are hugging, you give eachother two slaps on the back and say, "Not Gay", and immediately let go.

A handshake that transitions into a hug-like, semi-embrace that lasts no more than one second and may be accompanied by a firm slap on the back. An acceptable way for one guy to show appreciation for another male friend.

Man Hug (adj): an enfolding, friendly (completely platonic) embrace from a man/guy to a woman/ girl.

Given at the right time, a man hug will often markedly brighten a woman's day.
A "girl to girl" hug is usually less effective.
When a woman is particularly "blue," she sometimes, upon seeing a (male) friend, will smile widely and nearly jump into his arms for a man hug, throwing her arms around his neck to bring him to a more comfortable height. The man should squeeze tightly (not too tight!) and put his chin on her shoulder. Soft, contented chuckling from both is normal.