pleon/ˈpliːɒn/EtymologyBorrowed from New Latin, from Ancient Greek πλέων (pléōn), present participle of πλεῖν (pleîn, “to sail”); from the fact that it bears the swimming limbs. Alternatively, perhaps in the sense of being longer or extended.pleon means The abdomen of a crustacean. Lexicurio rates it Sui generis — a strength score of 87 out of 100.nounThe abdomen of a crustacean.