The song, which comes two years after she released "Talk a Good Game" album, was released via SoundCloud, reported Aceshowbiz.
"Dumb" is presumably a preview of former Destiny's Child singer's planned fifth album.
The club-friendly track has danceable beats.
"And if he really want some/ I make him treat it like a classic/ Make him want to do the nasty/ I make him go dumb dumb dumb dumb," Rowland sings.