stuff (usually uncountable, plural stuffs) (informal) Miscellaneous items or objects; (with possessive) personal effects. quotations Learn the meaning of stuff as a noun and a verb in English, with synonyms, idioms, and usage examples. Stuff can refer to a substance, a thing, a quality, or an action, depending on the context. 20 meanings: 1. to pack or fill completely; cram 2. to eat large quantities 3. to force, shove, or squeeze 4. to fill (food.... Click for more definitions. STUFF meaning: 1 : materials, supplies, or equipment; 2 : a group or pile of things that are not specifically described