The story
From moon + cusser: the strategy would not work on a moonlit night, so the would-be pirate might be expected to curse the Moon.
Etymology from Wiktionary, CC BY-SA 4.0.
mooncusser
Today it means: A land-based pirate who, on dark nights along dangerous coasts, would demolish any legitimate lighthouses or beacons, erect a decoy signal fire in a different, deliberately misleading location, and then, after having induced a shipwreck, subdue any survivors and plunder the wreckage for valuables. Full definition →