‘主义’ (zhǔ yì) is a noun suffix meaning ‘-ism’, used to form terms for ideologies, doctrines, or systematic beliefs—such as socialism, feminism, or environmentalism. It combines 主 (zhǔ), meaning ‘master’ or ‘central’, and 义 (yì), meaning ‘principle’, ‘righteousness’, or ‘meaning’. Together, they convey the idea of a guiding principle or foundational doctrine that governs thought or action.

This suffix appears almost exclusively in formal, academic, political, or philosophical contexts. It’s rarely used alone; instead, it attaches to nouns or adjectives to create compound terms (e.g., 资本主义 zīběn zhǔyì ‘capitalism’, 现实主义 xiànshí zhǔyì ‘realism’). While many English -isms have direct Chinese equivalents ending in 主义, not all English -isms map neatly—some require different constructions (e.g., ‘populism’ is often 民粹主义 mín cuì zhǔyì, literally ‘populist-ism’). Learners should note that 主义 is never used to describe personal preferences or casual habits (e.g., you wouldn’t say ‘coffee-ism’).