Buttercup is the name of several bands
1) A San Antonio indie-pop project featuring Erik Sanden on guitar and vocals, Jamie Roadman on drums, Joe Reyes on guitar, and Odie on bass. They released their first album "Sick Yellow Flower" in 2005, followed by "Hot Love" the next year and the EPs "Captains of Industry" and "Living Again" in 2007.
2) A Hungarian female metal band; see http://www.buttercupmusic.hu and http://www.myspace.com/buttercupband.
3) An Icelandic band.
4) Chop and screw artist.