commentariis
commentariis is a Latin form of commentarius, meaning “notebook, memoir, record (Caesar's Commentarii)”. It is the ablative plural masculine noun or dative plural masculine noun.
Found 68 times in the Latin texts on Socratos.
Where it is used
Caesar, De Bello Gallico 8.15.5: Fasces, ubi consederant (namque in acie sedere Gallos consuesse superioribus commentariis Caesaris declaratum est), per manus stramentorum ac virgultorum, quorum summa erat in castris copia, inter se …
Aulus Gellius, Noctes Atticae 3.12.1: BIBENDI avidum P. Nigidius in Commentariis grammaticisGranmmaticis bibacem et bibosum dicit.
All forms of commentarius (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.