Definitions for no one
Random House Webster's College Dictionary
no person; not anyone:
No one is home.
Category: Usage Note
* Usage: See each.
Origin of no one:
Kernerman English Learner's Dictionary
not one person; = nobody
She shouted for help, but no one heard.
not one person except the person mentioned
I went to the meeting, but no one else showed up.
Not one person, nobody.
The logical negation of someone.