mix, mingle, commingle, blend, merge, coalesce, amalgamate, fuse mean to combine into a more or less uniform whole.

mix may or may not imply loss of each element's identity.

mingle usually suggests that the elements are still somewhat distinguishable or separately active.

commingle implies a closer or more thorough mingling.

blend implies that the elements as such disappear in the resulting mixture.

merge suggests a combining in which one or more elements are lost in the whole.

coalesce implies an affinity in the merging elements and usually a resulting organic unity.

amalgamate implies the forming of a close union without complete loss of individual identities.

fuse stresses oneness and indissolubility of the resulting product.