a hug from the side, that usually includes a pay on the back so it doesn't appear romantic in any way, shape, or form.

Literally everyone, ever. Including the writer of this definition.

(a) when one, under the stress of the immediate situation, engages to hug a potential significant other and fails to conform to traditional hugging practices; (b) wrapping one's arms around the neck or head of a significant other in lieu of encroaching upon semi-romantic boundaries; (c) a metaphorical action telling one whom you have recently had sexual encounters with that a relationship is not in the immediate future; and (d) the awkward interaction that occurs when one is indecisive about crossing the friendship line.