Formal:
* پیرمرد (Pīrmard): This is the most common and neutral way to say "old man".
* سالمند (Sālemānd): This means "elderly" and is more polite and respectful.
Informal:
* پیر (Pīr): This is a more informal word for "old" and can be used to address an old man directly.
* بابا (Bābā): This means "father" but can also be used to address an old man in an affectionate or familiar way.
Other options:
* رَسِیده (Rasīde): This means "mature" or "ripe" and can be used to describe an old man in a positive way.
* مُسن (Mosann): This means "aged" or "elderly" and is more formal than "pīrmard".
The best way to choose the right term depends on the situation and your relationship with the person you are talking about.