Here's what rhymes with once.
Words that almost rhyme with once
ones month guns runs sons tons nuns tonnes suns amours buns puns comes lungs sums tongues gums thumbs bums glans rungs drums crumbs slums plums becomes succumbs overcomes us ups thus months bus cuts pulse cups nuts ducks huts pus fuss guts bucks butts cuffs hunts puffs shuts mus muss pups ruts shunts sucks plus flux monks trucks ducts fronts pumps chunks cults jumps lumps truss bluffs bumps busts crux cusps dumps gusts lusts stuffs tufts tusks beauteous bunks dusts grunts husks junks mumps pulps stunts adults trunks trusts clumps adjusts crusts repulse struts stumps thrusts corrupts drunks trumps woodcuts results discuss insults conducts confronts interrupts aqueducts coconuts consults disrupts superfluous instructs obstructs constructs