/ ɪnˈtruːʒn; NAmE / noun [ U , C ] intrusion (into / on / upon sth)
1.
something that affects a situation or people's lives in a way that they do not want :
They claim the noise from the new airport is an intrusion on their lives.
This was another example of press intrusion into the affairs of the royals.
2.
the act of entering a place which is private or where you may not be wanted :
She apologized for the intrusion but said she had an urgent message.
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WORD ORIGIN
late Middle English (in the sense invasion, usurpation ): from medieval Latin intrusio(n-) , from Latin intrudere thrust in, from in- into + trudere to thrust.