Slang spin off of the word nice. nice --> niche (n-eye-ch) --> sniche (sn-eye-ch). used to describe something either really cool, or sarcastically if it's just terrible.
Guy 1: I felt a sniche buzz in the middle of getting brain from that bittie from that forest lake party because i smoked the fanks right before she came.
Guy 2: Ohhh, SNICHE!