15-letter words containing m, a, s, r
- what's-her-name — a girl or woman whose name is unknown, temporarily forgotten, or deliberately overlooked
- white christmas — A white Christmas is a Christmas when it snows.
- white supremacy — the belief, theory, or doctrine that white people are inherently superior to people from all other racial groups, especially black people, and are therefore rightfully the dominant group in any society.
- william webster — Daniel, 1782–1852, U.S. statesman and orator.
- wrestling match — sport: contention by grappling opponent
- x-ray astronomy — the branch of astronomy that studies celestial objects by means of the x-rays emitted by them.
- zermelo's axiom — axiom of choice.