Sweat from the back region, particularly the small of the back, that turns your shirt game upside down. Grey t-shirts are particular harbingers of backspiration. The hotter and more humid it is, the bigger the backspiration stain. Sigh.
Backspiration is when someone sweats profusely from his/her back causing a big wet mark. Backspiration is an undesirable occurrence unless actively trying to ward off members of the opposite sex.
Normally I’m super embarrassed by my backspiration, but it sure does help keep Joe, that creep from accounting, at bay.
A backswitch is a word used to describe to a Minecraft noob, or someone who generally doesn't have a grip on reality. A Backswitch never thinks their wrong, and generally chooses to disagree whenever they can.
"I was giving a captivating speech to an enthralled crowd. When all of a sudden, some loony starts shouting about their stupid position. I hate backshit like that."