marker (n.)youdaoicibaDictYouDict[marker 词源字典]
Old English mearcere "writer, notary" (glossing Latin notarius "clerk"), literally "one who marks," agent noun from mark (v). Not found again until late 15c., hence modern use is perhaps a separate formation. Meaning "monument stone" is from 1888. Meaning "felt-tipped marker pen" is from 1951, so called because their purpose was to "highlight" text.[marker etymology, marker origin, 英语词源]