Formal:
* Ancient: Implies great age and often historical significance.
* Venerable: Suggests respect and age-related wisdom.
* Timeworn: Emphasizes the effects of time.
* Antique: Refers to objects of historical or artistic value.
* Hoary: Suggests a white or gray appearance due to age.
* Aged: More neutral than "very old."
Informal:
* Ancient: (Can be informal, depending on the context)
* Really old: Simple and straightforward.
* Old as the hills: Hyperbolic and playful.
* Long in the tooth: Informal and sometimes humorous.
* Getting up there: Suggests someone is nearing the end of their life.
* Has seen better days: Implies deterioration due to age.
Specific to objects:
* Vintage: Refers to items from a specific past period.
* Used: A general term for something that has been previously owned.
* Pre-owned: More formal than "used."
* Second-hand: Refers to something bought or received from someone else.
The best word to use will depend on the specific situation and the tone you want to convey.