The word "mainstays" refers to the primary or essential components that support or sustain a system or structure. Synonyms for "mainstays" include cornerstones, foundations, pillars, keystones, anchors, linchpins, bedrocks, essentials, fundamentals, and key elements. Each of these synonyms emphasize the importance of the identified component and its integral role in maintaining the stability and functionality of the whole. Whether describing the critical components of a business model, political system, or personal belief system, the use of these synonyms for "mainstays" allows for a clear and concise understanding of the key components that lie at the heart of a given system or structure.