doormat, weakling, wuss - a person who is physically weak and ineffectual

natural philosophy, physical science, physics - the science of matter and energy and their interactions

acronym - a word formed from the initial letters of a multi-word name

elementary particle, fundamental particle, subatomic particle - a particle that is less complex than an atom; regarded as constituents of all matter

dark matter - (cosmology) a hypothetical form of matter that is believed to make up 90 percent of the matter in the universe; it is invisible (does not absorb or emit light) and does not collide with atomic particles but exerts gravitational force