theatrical (adj.)youdaoicibaDictYouDict[theatrical 词源字典]
1550s, "pertaining to the theater;" see theater + -ical. Sense of "stagy, histrionic" is attested from 1709. Related: Theatrically; theatricality.[theatrical etymology, theatrical origin, 英语词源]
theatrics (n.)youdaoicibaDictYouDict
1807, "matters pertaining to the stage," from noun use of theatric (adj.) "pertaining to the theater" (1706), from theater. Meaning "theatrical behavior" is attested from 1929, American English.