Everyone defined "ignore" differiently from past experiences and perspective.
Being ignored, in my opinion, is an action where the individual pretend it's not there.
A christmas carol has a metaphor
"The streets reeked of crime"
John Snow is known as the father of epidemiology.
In this essay "On the Mode of Cholera" he used both reasoned argument along with documentary evidence to show that cholera spread from person to person.
He gave examples of rows of houses on opposite sides to each other, and how all of the members in one row contracted cholera, while only one person on the opposite row contracted the disease.