Mallemaroking was the carousing of seamen on board Greenland whaling ships.
You must agree that no true student of the English language can afford to be without this choice specimen of exact usage. Not, you will note, just any seamen aboard any ships, but whalers in the Greenland waters, who were — it seems — always ready for a bit of merry-making in between hunting the Greenland right whale. (This whale name was another term from the same fishery, too mundanely derived to deserve much attention from word historians, since it was merely the whale found around Greenland that was the right one to hunt.)
The word owes its survival almost entirely to its curious form and peculiarly precise nature. There is little chance that it will ever be found unselfconsciously used as the right word in the right place. It is the preserve almost solely of those wordsmiths who write about Weird Words, a sad degeneration of status in whose reduction my own small part is all too obvious.
The word is said to derive from Dutch mallemerok, a foolish woman or tomboy. This derives from mal, foolish, plus a word that comes from French marotte, an object of foolish affection. How this skittish Dutch lady found her way to Greenland, and gave her name to the carousing of whalers, must be left to the imaginations of readers.