An anachronism (from the Greek "ανά", "against", an "χρόνος", "time") is anything that is temporally incongruous in the time period it has been placed in—that is, it appears in a temporal context in which it seems sufficiently out of place as to be peculiar, incomprehensible or impossible. The item is often an object, but may be a verbal expression, a technology, a philosophical idea, a musical style, a material, a custom, or anything else closely enough bound to a particular period as to seem odd outside it.