invasion

plural invasions

1. countableuncountableA 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 Polish), →ISBN, →OCLC, page 402

   3 more examples

   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

   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.

   2022 July 7, “Inspired by Ukraine, civilians study urban warfare in Taiwan”, in France 24, archived from the original on 07 Jul 2022

   North Korea had not publicly confirmed its contribution until Monday, when it said: “The operations for liberating the Kursk area to repel the adventurous invasion of the Russian Federation by the Ukrainian authorities were victoriously concluded,” according to state-run news agency KCNA.

   2025 April 28, Helen Regan, Michael Rios, Darya Tarasova, Tim Lister, “Putin thanks North Korea for help in Kursk, as Germany criticizes US plan for Ukrainian concessions”, in CNN, archived from the original on 14 Aug 2025

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

   an invasion of bees

   2 more examples

   an invasion of mobile phones

   an invasion of foreign tourists

   Synonyms: descent

3. countableuncountablemedicineThe 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 the original on 23 Mar 2025

4. countableuncountablemedicineThe breaching of the skin barrier.