Here are some synonyms for "old":
- Aged
- Elderly
- Ancient
- Antique
- Mature
- Senior
- Vintage
- Timeworn
- Hoary
- Weathered
- Worn
- Obsolete
- Historic
- Dilapidated
- Preserved
The choice of synonym may vary based on context, so consider the nuance you wish to convey when selecting a replacement.