A form of manspreading in which one obliviously stands or walks in someone's way. Typically a behavior attributed to white men.
Two white guys are standing at the bottom of the staircase talking. Jen and Alex try to get down the stairs.
Jen: Impedimanning.
Alex: What do we do?
Jen: We just push through and act like its our fault.
The two push through and say sorry. Neither impediman notices.