coloniser

Coloniser means to colonize — historically, one country or people taking political and economic control of another territory (la France a colonisé l'Algérie), and more loosely today for any dominant, unwanted expansion (une espèce qui colonise un territoire, un marché colonisé par une entreprise).

• La France a colonisé plusieurs pays d'Afrique du Nord et d'Afrique de l'Ouest. — France colonized several countries in North and West Africa.
• Cette espèce invasive colonise rapidement les rivières européennes. — This invasive species is rapidly colonizing European rivers.
• Les moisissures ont colonisé tout le mur humide. — The mold colonized the entire damp wall.

In a historical or political context, coloniser is not a neutral, technical word in French — like collaborer, it carries the full moral weight of the colonial history it describes, and using it casually about that period can read as minimizing it.

• book Discours sur le colonialisme — Verified: Aimé Césaire's 1950 anti-colonialist essay, which includes the widely cited line "nul ne colonise innocemment, que nul non plus ne colonise impunément" (no one colonizes innocently, and no one colonizes with impunity).