filling (adj.)youdaoicibaDictYouDict[filling 词源字典]
"calculated to fill or satisfy," 1620s, present-participle adjective from fill (v.).[filling etymology, filling origin, 英语词源]
filling (n.)youdaoicibaDictYouDict
c. 1400, "that which fills or fills up," verbal noun from fill (v.). Dentistry sense is from 1848. Filling station attested by 1915.