early 14c., "metal-pointed missile weapon thrown by the hand," from Old French dart "throwing spear, arrow," from Proto-Germanic *darothuz (source also of Old English daroð, Old High German tart "a dart, javelin," Old Norse darraþr "dart"). Italian and Spanish dardo are said to be from Germanic by way of Old Provençal. Also used since Middle English of Cupid's love-arrows. Dart-board is from 1901.
late 14c., darten, "to pierce with a dart" (a sense now obsolete), from dart (n.). Sense of "throw with a sudden thrust" is from 1570s. Intransitive meaning "to move swiftly" is from 1610s; that of "spring or start suddenly and run or move quickly" (like a dart) is from 1610s. Related: Darted; darter; darting.