proin
proin is a Latin form of proinde, meaning “therefore, accordingly; (proinde ac) just as”. It is the adverb.
Found 30 times in the Latin texts on Socratos.
Where it is used
Cicero, De Divinatione 1.45: … ántes agitantque, éa si cui in somno áccidunt, mínus mirum est; séd in re tanta haud temere visa se ófferunt. próin vide ne, quém tu esse hebetem députes aeque ác pecus, is sapientiá munitum péctus egregié gerat téque regno e …
Tacitus, Annales 1·95: … ducum, funditus amissas nobilis familias constanter tulerit. principes mortalis, rem publicam aeternam esse. proin repeterent sollemnia, et quia ludorum Megalesium spectaculum suberat, etiam voluptates resumerent. Tum exuto …
Terence, Heautontimorumenos 1.2.177: Proin tu sollicitudinem istam falsam quae te excruciat mittas.
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.