mesostichEtymologyFrom Ancient Greek μέσος (mésos, “middle”) and στίχος (stíkhos, “line”).mesostich means an acrostic that spells out a word or message with its middle letters. Lexicurio rates it Sui generis — a strength score of 87 out of 100.nounAn acrostic that spells out a word or message with its middle letters.