sescenaris

Conventionally explained as a corruption of a hypothesised *sēscennālis, from sēsqui- (“one and a half”) +‎ annālis (“yearly”); compare decennālis (“ten-yearly”). However, Lewis and Short regard as "improbable" the "conjectural correction" to *sēscennālis or alternatively to sexennis (“six-year-old”).

• (Classical Latin) IPA^(key): [seːs.keːˈnaː.rɪs]
• (modern Italianate Ecclesiastical) IPA^(key): [seʃ.ʃeˈnaː.ris]

sēscēnāris (neuter sēscēnāre); third-declension two-termination adjective

1. (hapax legomenon) The meaning of this term is uncertain. Possibilities include: one and a half years old
   • 27 BCE – 25 BCE, Titus Livius, Ab Urbe Condita 41.15.1:

     exposuit patribus conscriptis bovis sescenaris, quem immolavisset, iocur diffluxisse

     he explained to the senators that the liver of the […] ox which he had sacrificed had disappeared

Third-declension two-termination adjective.

• “sescenaris”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “sescenaris”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• “sescenaris”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.