Maghrib is the fourth daily salat in Islam,
offered at sunset. The word maghrib is an Arabic term for "of
the setting (sun)"; from the root "ghuroob", "to set"; "to be
hidden" (but it is not used for the setting of the moon). It is
also used in a manner similar to the metaphorical use of "to be
eclipsed", which is used in the English language.
