A negative, zero social life, loser who knocks other peoples hobbies. Wether they be hunting to football to BMx to D&D, a Hob Knocker will tear down what some people choose to do with their free time, compared to a Hob Knocker who sits on his/her ass in his parents basement looking at pictures and youtube videos of people actually doing shit with their lives.
Regular Guy: I'm going camping this weekend, what about you?
Hob Knocker: *scoffs* Camping??!?! What is this brokeback mountain? So lame.
Regular Women: I'm going to paint a few pictures over summer break!
Hob Knocker: LOL! FAIL! Painting!?!!? You're not making any money on that crap you call painting, so why continue?
Young Kid: I'm going to go BMX riding with my friends!
Hob Knocker: Seriously? What happend when you fall on your ass and crack your head open? YOU COULD DIE! LOL
Young Kid:.....You Hob Knockers have no lives what so ever.
2. to refer to a person as the pain one suffers after being hob-knocked
On ICarly and Friends the runner up to David Archuleta calls everyone Hob-knockers, hob-knocked is to get hit hard in the testicles ergo a hob-knocker...