10 letters · 17 points in Scrabble
noun an aircraft without wings that obtains its lift from the rotation of overhead blades
originBorrowed from French hélicoptère, from Ancient Greek ἕλιξ (hélix, “spiral”) + πτερόν (pterón, “wing”). Doublet of helicopteron. By surface analysis, helico- + -pter. The dragonfly sense is from a dragonfly's ability to hover and fly in any direction, like the flying machine.
Etymology from Wiktionary, CC BY-SA 3.0