Aged, elderly & senior are all synonyms for old.
Fossil is a synonym of old and antique and begins with an F.
The answer to that question, what is the synonym of old?, is worn out. new
old, getting on, grey, ancient, antique, elderly
old fashioned
Elderly or aged
a synonym for eldest is oldest or old because the saying always respect your elders
Old man's beard.
ancient, aged, old
old-fashioned
expired or old
unusual, extraordinary, old-fashioned
dated, antiquated, outdated, old