The word 呼唤 (hūhuàn) is formed through the morphological process of compounding, where two independent, synonymous monosyllabic characters are combined to create a single disyllabic word with a reinforced and more abstract meaning. The character 呼 (hū) primarily means "to exhale" or "to shout", while 唤 (huàn) means "to call out" or "to summon". When paired, their semantic fields overlap and intensify, producing the combined meaning of "to call out to", "to appeal to", or "to summon", often carrying connotations of earnestness or urgency that neither character possesses alone. This structure is a classic example of a synonym compound (并列式复合词) in Chinese, where two similar morphemes unite to form a cohesive concept with nuanced depth.