Tomboy rhymes with:
farmboy, lamboy, attaboy, brayboy, busboy, carboy, cowboy, doughboy, farmboy, highboy, lamboy, littleboy, playboy, schoolboy
Tomboy sounds like:
tambo, tamp, tampa, tampopo, tanabe, temp, tempe, tempo, thomp, thumb, thump, tien-fu, timpe, tomb, tuneup