invasion

Noun

invasion (countable and uncountable, plural invasions)

1. 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.
   • The invasion and armed suppression, on one occasion after another, of nations seeking to be free was quite consistent with Lenin's views.1978 [1976], Leszek Kołakowski, translated by P[aul] S[teven] Falla, Main Currents of Marxism, volume II: The Golden Age, Oxford: Clarendon Press, translation of Główne nurty marksizmu: rozwój (in...
   • 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.2003, Lawrence Murray, The Kassandra Complex
2. 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

   Synonyms:

   descent

3. 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.2015 September 8, Filomena Cetani et al., “A nonfunctioning parathyroid carcinoma misdiagnosed as a follicular thyroid nodule”, in World Journal of Surgical Oncology, volume 13, →DOI, archived from...
4. The breaching of the skin barrier.