A synonym for producer, but not so much because a producer's task may be a little more complex than a beatmaker. Basically the person who does the beat for a song, including melody, samples, etc. More common in hip hop and rap than any other form of music.
Yo fam, who's a better beatmaker, Kanye West ot Just Blaze? I mean, "Song Cry" was hot, don't get me wrong, but "Heart of the City" and "Takeover" got hotter beats! Kanye is the man for making those beats!!!
*All aforementioned songs are on Jay-Z's 2001 album, "The Blueprint".