Carbonem
Carbonem is a Latin form of carbo, meaning “charcoal, glowing coal; (Carbo) a Roman family name”. It is the accusative singular masculine noun.
Found 30 times in the Latin texts on Socratos.
Where it is used
Cicero, In C. Verrem 1.1.11: … escentiae maculas ignominiasque praeteream, quaestura, primus gradus honoris, quid aliud habet in se nisi Cn. Carbonem spoliatum a quaestore suo pecunia publica, nudatum et proditum consulem, desertum exercitum, relictam provinc …
Vitruvius, On Architecture 2.9.14: … ardere, nisi uti saxum in fornace ad calcem coquendam aliis lignis uratur; nec tamen tunc flammam recipit nec carbonem remittit, sed longo spatio tarde comburitur. namque ea materies, quod est minima ignis et aeris e principiis …
All forms of carbo (declension table)
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Lewis & Short, A Latin Dictionary (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.