inline (adj.)youdaoicibaDictYouDict[inline 词源字典]
1923 of printing, 1929 of engines, 1958 of computers, by 1989 of roller skates; from in + line (n.).[inline etymology, inline origin, 英语词源]
skate (n.2)youdaoicibaDictYouDict
"ice skate," 1660s, skeates "ice skates," from Dutch schaats (plural schaatsen), a singular mistaken in English for plural, from Middle Dutch schaetse. The word and the custom were brought to England after the Restoration by exiled followers of Charles II who had taken refuge in Holland.

The Dutch word is from Old North French escache "a stilt, trestle," related to Old French eschace "stilt" (French échasse), from Frankish *skakkja "stilt" or a similar Germanic source (compare Frisian skatja "stilt"), perhaps literally "thing that shakes or moves fast" and related to root of Old English sceacan "to vibrate" (see shake (v.)). Or perhaps [Klein] the Dutch word is connected to Middle Low German schenke, Old English scanca "leg" (see shank). Sense alteration in Dutch from "stilt" to "skate" is not clearly traced. Sense in English extended to roller-skates by 1876. Meaning "an act of skating" is from 1853.
skater (n.)youdaoicibaDictYouDict
1700, "one who ice-skates," agent noun from skate (v.). Extended to skateboarders by 1977.