caller (n.)youdaoicibaDictYouDict[caller 词源字典]
c. 1500, "one who proclaims," agent noun from call (v.). Meaning "one who announces step changes at a dance" is recorded from 1882; "one who places a telephone call," 1898. Meaning "a social visitor" is attested from 1786.[caller etymology, caller origin, 英语词源]