The 10-letter word meaning “to mix or blend together in a homogeneous body” is amalgamate.
To amalgamate means to combine separate things into one unified whole. It can describe substances, ideas, organizations, or groups. The related noun amalgamation refers to the process or result of combining them, while amalgam originally described a mixture of mercury with another metal.
The word is especially common in formal writing about business, government, military units, and society. For example, two companies may amalgamate into one organization, or distinct traditions may amalgamate into a shared culture. In each case, the emphasis is on joining elements so they function as a single entity.
A nearby word is “merge,” but amalgamate can carry a stronger sense of blending or integration. “Mix” is broader and may describe a temporary combination, whereas amalgamate often suggests a more complete or lasting union. The spelling has ten letters: a-m-a-l-g-a-m-a-t-e.