A parachronism (from the Greek "παρά," "on the side," and "χρόνος," "time") is anything that appears in a temporal context in which, though not sufficiently out of place as to be impossible, is not normally found in that time period. 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 strange when viewed in a later time period.
Parachronisms are usually seen as objects or ideas which were once common, but are now considered rare or inappropriate. They often take the form of obsolete technology or outdated fashion. This is different from an anachronism, in which the object or idea in question had not yet been invented when the situation takes place, and is therefore impossible to have existed at that time.