topical (adj.)youdaoicibaDictYouDict[topical 词源字典]
1580s, "pertaining to a place;" see topic + -al (1). Medical sense "applied to a particular part of the body" is from c. 1600. Meaning "of or pertaining to topics of the day" is from 1873. Related: Topically.[topical etymology, topical origin, 英语词源]