"Spawning" has different meanings, by context.
1. When creatures first appear on the map, it is referred to as "spawning"
2. However, there are types of localized boss fights called "Champion Spawns", where waves of creatures spawn (as in the first definition), progressively getting to more difficult types, until the Champion itself spawns. "Spawning" is sometimes used as a term for going to such spawns, to try to gather scrolls (Scrolls of Power, Scrolls of Transendence, etc.), or to attack those doing such spawns in Felucca ("raiding a spawn").