acerbius
acerbius is a Latin form of acerbus, meaning “bitter, harsh, sour; painful; untimely”. It is the comparative adverb.
Found 43 times in the Latin texts on Socratos.
Where it is used
Caesar, De Bello Gallico 7.17.4: Quin etiam Caesar cum in opere singulas legiones appellaret et, si acerbius inopiam ferrent, se dimissurum oppugnationem diceret, universi ab eo, ne id faceret, petebant:
All forms of acerbus (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.