| Main Entry: | |
| Part of Speech: | verb |
| Definition: | obsolesce |
| Synonyms: | date, go extinct, obsolete, superannuate |
| Main Entry: | obsolesce |
| Part of Speech: | verb |
| Definition: | fall into disuse |
| Synonyms: | go extinct, obsolete, outdate, retire, superannuate |
| Main Entry: | superannuate |
| Part of Speech: | verb |
| Definition: | obsolesce |
| Synonyms: | date, go extinct, obsolete, outdate |
| Main Entry: | archaic |
| Part of Speech: | adjective |
| Definition: | very old |
| Synonyms: | ancient, antiquated, antique, bygone, obsolete, old-fashioned, olden, out of date, outmoded, passé, primitive, superannuated |
| Antonyms: | current, modern, new, present, young |
| Main Entry: | behind the times |
| Part of Speech: | adjective |
| Definition: | not current |
| Synonyms: | antiquated, back-number, dated, has-been, obsolete, of the old school, old hat, old hat, old-fashioned, out of date, out-of-date, outdated, outmoded, passe, square, unfashionable |