will a glitch is were some one trys to use a item in the map to take advantage of and were it normal not use at all. sample say a build has a fake wall were you can goes through it without no cheat items at all and start shooting every one from under it, (node them from under the floor) and they can't see you. there is some buildings i have seen that the walls every one can walk through them a good map maker use a fencing to cover or block it off from being use, any time a player use something in a building or terrain and its a weak point easy to take advantage of this is call glitching or using a glitch item in the map area.
mostly doing something that not normal in a game, most i seen is some using the buildings hidden behind a wall small or big don't matter any on the rooftop laying low in a corner or inside a very big tree to pop-out then make the kill and pop-in to it. any time one dose thing it is most part glitching in the game in BHD you may even see some hill top you lay low in some spot you can see through the area on the terrain. some games have their bad spot were it was not made to good or fore gotten. using a glitch is a "BIG FAT NO" some have gotten banned for this. and some host out-side Nova-stats servers will not give a warning on it. best stay away from glitches of any type you find it move away from it and say no then to no one about it. you can report it to
support@novalogic.com and let them know of it only. what map name is and server name it was in so they maybe able to fix it, they are really slow on this type of fix's