Recycle in WoW does not refer to biodegradable materials. Perhaps re-cycle would be more appropriate.
Items and abilities with a cooldown have a timer before they may be reused. Waiting for this turnaround period to complete is known as recycling. Although the term is a carryover from other games, it has seen dramatically less use recently, as players simply refer to the whole process as "cooldowns" and "completing cooldowns."