The word "讶异" is formed by combining the character "讶", meaning to express surprise or astonishment, derived from the semantic component "言" (speech) and phonetic "牙", with the character "异", meaning unusual or different, originally depicting something strange. Together, they create a compound where "讶" conveys the emotional reaction of surprise and "异" emphasizes the uncommon nature of what prompts it, resulting in the meaning of being amazed or astounded.