Detach
Detach refers to the act that results to send an Xyz Material attached to an Xyz Monster to the Graveyard, either as a cost or by an effect (that uses this term).
When a Xyz Material is detached, it is not treated as it leaving the field, since Xyz Materials are not treated as being on the field; so the effects of monsters like "Sangan" or "Card Trooper" and the conditions of monsters like "Plaguespreader Zombie" are not applied.