What does lētāliter mean in Latin?

lētāliter, a adverb, means “lethally, mortally”.

How do you pronounce lētāliter?

In classical Latin, [ɫɛˈta.lɪ.tɛr]; in ecclesiastical (church) Latin, [leˈtaː.li.ter].

adverb

lētāliter (comparative lētālius, superlative lētālissimē)

Classical[ɫɛˈta.lɪ.tɛr]Ecclesiastical[leˈtaː.li.ter]

lethally, mortally
et quia languente dextera, letaliter ferire non potuit, iam districtum mucronem in proprium latus inpegit.380 CE – 392 CE, Ammianus Marcellinus, Res Gestae 14.5
nec contenta ictos letaliter ire per artus, / coniungit mortes una sagitta duas.and not content to lethally drive its course through the stricken limbs, a single arrow deals two deaths at once.c. 310 CE – c. 394 CE, Ausonius, Epigrammata Ausonii de diversis rebus 27

mortiferē

lētāliter — in IVLIANVS III: Persia, ch. 17

Proto-Indo-European *-teros? Latin -ter Latin lētāliter From lētālis (“lethal, deadly”) + -ter.