What is the meaning of Old_man?

An elderly man.

One's father.

A husband, or male significant other, irrespective of age.

One's male employer, irrespective of age.

A unit's commanding officer, or the commander of a naval vessel, irrespective of age.

Term of address for a male friend, irrespective of age.

Synonym of Old Adam

Synonym of southernwood

The state of human nature without the spiritual transformation brought about by redemption through Jesus Christ.

Used attributively to denote something of exceptional size, strength, age etc.

Source: wiktionary.org