The word 小道 (xiǎo dào) is a compound noun formed through semantic combination, where the independent character 小 ("small; minor") modifies the core character 道 ("path; road; way"). This creates a primary literal meaning of "a small path" or "bypath." By figurative extension, this structural concept of a "minor way" is then applied metaphorically to common idioms: it refers to "unofficial news" (gossip or hearsay, as information arriving via informal, side channels) and, in contexts like 小道消息, to minor or unorthodox branches of study or practice, contrasting with the "main road" (大道) of orthodox knowledge.