Today marks one of the greatest eclipses in modern American history, so this seemed appropriate. The word eclipse as a verb and noun both comes from its Old French cognate eclipse, which took the usual route through Latin eclipsis to trace back to Greek ekleipsis. It isn't surprising that it derives from Greece because of all those fancy astronomers naming stuff in the Classical Age, if you think about it. Anyway, ekleipsis derives from ekleipen, which once meant "a forsaking or abandonment" (of the sun, makes sense) but more literally had a definition of "leaving out". Etymologically it meant that too: the prefix ek- meant "out", from the previously covered PIE root eks (also "out"), and the root lepein meant "to leave" and may be followed to another Proto-Indo-European root; leykw, also "leave". Recent google trends saw "eclipse" searches skyrocket, though long-term usage has actually decreased somewhat.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.