not personal; without reference or connection to a particular person: an impersonal remark.
2.
having no personality; devoid of human character or traits: an impersonal deity.
3.
lacking human emotion or warmth: an impersonal manner.
4.
Grammar.
a.
(of a verb) having only third person singular forms and rarely if ever accompanied by an expressed subject, as Latin pluit “it is raining,” or regularly accompanied by an empty subject word, as English to rain in It is raining.
b.
(of a pronoun or pronominal reference) indefinite, as French on “one.”
–noun
5.
Grammar. an impersonal verb or pronoun.
Origin: 1510–20; < LL impersōnālis.See im-2, personal
Lacking personality; not being a person: an impersonal force.
Showing no emotion or personality: an aloof, impersonal manner.
Having no personal reference or connection: an impersonal remark.
Not responsive to or expressive of human personalities: a large, impersonal corporation.
Of, relating to, or being a verb that expresses the action of an unspecified subject, as in methinks, "it seems to me"; Latin pluit, "it rains"; or, with an expletive subject, it snowed.
Indefinite. Used of pronouns.
Grammar
Of, relating to, or being a verb that expresses the action of an unspecified subject, as in methinks, "it seems to me"; Latin pluit, "it rains"; or, with an expletive subject, it snowed.
[im-pur-suh-nl] 
sə