to cause to combine or coalesce; unite.

to combine, blend, or unite gradually so as to blur the individuality or individual identity of

They voted to merge the two branch offices into a single unit.

to become combined, united, swallowed up, or absorbed; lose identity by uniting or blending (often fol. by in or into )

This stream merges into the river up ahead.

to combine or unite into a single enterprise, organization, body, etc.

The two firms merged last year.