8 letters · 17 points in Scrabble
noun a circle that rolls around (inside or outside) another circle; generates an epicycloid or hypocycloid
originFrom Latin epicyclus, from Ancient Greek ἐπίκυκλος (epíkuklos), from ἐπί (epí, “upon”) + κύκλος (kúklos, “circle”). The ad hoc complication sense is a generalization from the archetype supplied by the Ptolemaic astronomy sense.
Etymology from Wiktionary, CC BY-SA 3.0