捡垃圾 means 'to pick up litter' — literally 'pick up' (捡) + 'garbage' (垃圾). It describes the physical action of collecting discarded items like bottles, paper, or food wrappers from public spaces such as parks, streets, or beaches. Though composed of three characters, it functions as a single verb phrase and is commonly used in environmental education, community service, and daily life contexts.

This term carries a positive connotation when referring to voluntary, responsible behavior — for example, students cleaning a schoolyard or volunteers organizing a neighborhood cleanup. It’s not used for professional waste collection (which uses terms like 清运 or 收集垃圾), nor for picking up trash in private indoor settings (where 扔垃圾 or 倒垃圾 would be more appropriate). The word emphasizes intentionality and civic care rather than mere disposal.