This word is largely undefinable, but here are possible usages for it...
1. An exclamation of good happenings. A celebratory word along the lines of "tight" or "fuck yeah"...
2. A declaration of crappy circumstances. A word used following a disappointing turn of events similar to "damn" or "this sucks"...
3. Icicles forming beneath the taint forming as the result of extreme cold.
"I hooked up with a hottie last night! Taintsicle yeah!"
"I hooked up with an ugly ho last night! Ah taintsicle!"
"It's so freaking cold out that GD taintsicles are forming beneath my taint!"