merge 一つになる 同化する
if one things merges with another, or is merged with another, they combine or come together to make one whole thing. You can also say that two things merge, or merged.
（例文）
Bank of America merged with rival bank.
if one sound , color, or object merges into another, the first changes so gradually into the second that you do not notice the change.
ex
Like a chameleon, he could merge unobtrusively into the background
