The act of negotiating a meeting time by listing your available times for a meeting to others, and hoping one of those times hits an available time from the other parties to the meeting.
Glad you can make that time; calendar battleship is exhausting.
When one computer service calls another service, which calls back into the original service, suggesting a messy entanglement that cannot be easily separated. For example, if a social network contacts a search service to gather information, and the search service contacts the social network to finalize its results, we have created service spaghetti.
Our systems have become service spaghetti, entangled and interdependent in ways that are out of control.