ūndecim

Meaning

1. indeclinableeleven; 11
   ubi et ipse Cn. Fuluius cum undecim tribunis militum ceciditIt was here that Cn. Fulvius fell together with eleven military tribunes.27 BCE – 25 BCE, Titus Livius, Ab urbe condita 27
   stans autem Petrus cum undecim levavit vocem suam et locutus est eis viri iudaei et qui habitatis Hierusalem universi hoc vobis notum sit et auribus percipite verba meaBut Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judaea, and all ye that dwell at Jerusalem, be this known unto you, and hearken to my words:c. 347 CE – 420 CE, Hieronymus, Vulgate Actus Apostolorum.2.22

Latīnē defined in Latin in our graded readers

Origins

From earlier *oinodecem, from Proto-Indo-European *óynom déḱm̥t, corresponding to ūnus (“one”) + decem (“ten”).