An expression that can be used before doing something purely idiotic or stupid.
“Clay sliced off his cock, right before he did it he yelled gunga din.”
This word can be used as a verb, noun or adjective but typically is used if a said object is considered bad or broken.
“I was trying to stick my dick in the vacuum but it just ended up making the whole machine jank”
“You really janked up your sister last week”
“Yea my kid said you’re really jankey at giving head”