The standard etymological dictionaries of Greek mention two possible etymologies for the word σειρήν ‘siren’: a relationship either with σειρά ‘cord, rope’, or else with Σείριος ‘Sirius, the dog star’. Neither of these is very convincing on semantic and morphological grounds. The Mycenaean word se-re-mo- shows that the lexeme was originally an m-stem, and both the scarcity of m-stems in Greek and Indo-European and the presence of an initial s- that has not become an aspirate point to a non-Indo-European origin of the word. In the past, some scholars proposed that it must be a Semitic loanword related to the root of Hebrew šîr ‘sing’, but these explanations suffered from certain flaws in the detail. Meanwhile, Ugaritic šrm, a dual or plural of the word šr ‘singer’, appears to be a good candidate as the source of Gr. σειρήν. This assumption also suits the cultural and chronological context in which speakers of Greek in the second millenium BC are expected to have adopted the word.