Miley Cyrus -- Screw Twerking, I've Got a NEW DANCE!!

Miley Cyrus is giving her ass cheeks a rest ... at least on the dance floor ... where she's traded out her twerking-obsession for a NEW lame white person dance ... and TMZ has the footage!!!

The 21-year-old was gettin' down at LIV nightclub in Miami on Friday when she unleashed the new move -- which involves gyrating and invisible hair washing.

No word on what Miley calls her new move, but we've come up with a few suggestions ...

1) Dude, Where's My Hair?

2) Weave Can't Stop

3) The Dinglehopper Stroke ("Little Mermaid" reference, look it up)

Got a better one?