Metachronistic is a seldom-used term that refers to something occurring at a time different from that which would be expected. Synonyms for this word are few and far between, but they do exist. Some alternative phrases that can be used in place of metachronistic include anachronistic, untimely, out-of-phase, non-synchronous, mistimed, or asynchronous. These synonyms suggest something that is out of step with the times, out of sync with the normal rhythm, misplaced, or misaligned. All of these words convey the same meaning as metachronistic, but they may be more commonly used and better understood by a wider range of people.