invasion

A military action consisting of a large armed force of one geopolitical entity entering territory controlled by another such entity, generally with the objective of conquering territory or altering the established government.

Since Michel's days, however, many barbarian invasions had subdivided the Three Gauls into a melange of warsome states and tribes, all, nevertheless, acquiring a vaguely similar grace, if not a petite grandeur.

Yeh actually works in marketing, and his weapon is a replica -- but he is spending the weekend attending an urban warfare workshop to prepare for what he sees as the very real threat of a Chinese invasion.

The entry without consent of an individual or group into an area where they are not wanted.

an invasion of mobile phones

an invasion of bees

The spread of cancer cells, bacteria and such to the organism.

The histological diagnosis of PC is currently restricted to lesions showing unequivocal extra-parathyroidal growth, as evidenced by perineural invasion, full thickness capsular invasion with growth into adjacent tissues, extratumoral vascular invasion, or metastasis.

The breaching of the skin barrier.