- Noun Any small settlement of creatures, usually the size of a village and smaller than a town, lacking significant buildings.
- Noun Where a mob spawns or where mobs spawn.
- Verb Monopolize a camp.
- Verb Staying in the same area as a player or mob to do the same repetitive actions.
- Verb "Res camp", short for "Resurrection camp", is when a player waits near an opposing player's body for them to resurrect, allowing them to kill the player easily and without warning. This is considered a form of cheating and/or harassment and can result in punishment to the camper(s).
In World of Warcraft
This section concerns content exclusive to World of Warcraft.
Also, in World of Warcraft, the slash command /camp logs you off and takes you back to the character select screen.
A camp is a type of settlement. Several types exist: Abandoned camp, Camp, Druidic encampment, Encampment, Military camp, Military encampment, Mining camp, and Ruins/Military camp. They range in population from 50-3000. This would put them in the population range of many villages. 
Camping a player character from a roof top or other game geometry is generally considered abuse and is not allowed.