M&Aalso: エムアンドエーMeanings1nounM&A; mergers and acquisitionsbusinessBusiness term for corporate mergers and acquisitions. Used as a noun.その会かい社しゃはM&Aで急きゅう成せい長ちょうした。The company grew rapidly through M&A.M&Aの専せん門もん家かを雇やとう企き業ぎょうが増ふえている。More companies are hiring M&A specialists.