The word 充斥 is a disyllabic compound verb formed by combining two synonymous or related characters: 充 (chōng), which means "to fill" or "to be full", and 斥 (chì), which in this classical context means "to spread out" or "to expand". Together, they create an intensified meaning of "to flood", "to fill to overflowing", or "to permeate", almost always carrying a negative connotation of being filled with something undesirable (e.g., bad products, false information). This structure follows a common pattern in Chinese word formation where two morphemes with similar meanings are paired to reinforce and specify the overall concept.