One who inadvertently sits on the television remote control and thereby changes the channel.
As in: I was happily watching Debbie Does Dallas when at the vinegar strokes my fatrump eased over on to the remote and arseflicked the channel to Loose Women. I felt like such an arseflicker.
A mildly affectionate term for a person who has the tendency to be a total blundering oaf (mostly unwittingly possibly, but not completely devoid of wit and charm - making it somewhat perplexing for the onlooker).
"That is the moststunning lack of awareness I have ever come across! Or does he mean to be such a shit? *What* an arsebuckle!