godan verb (-su), transitive verb
Rare, literary, or old-fashioned verb. In modern Japanese, 許す (ゆるす) is the usual word for these meanings.
古い文書では「罪を仮す」のように使われることがある。
In old documents, it is sometimes used as in 罪を仮す (to forgive a sin).
許す is the standard modern word for 'to forgive', 'to allow', or 'to permit'. 仮す is a rare, literary equivalent.
The historical derivation is uncertain. The kanji 仮 (temporary, provisional) is used, but the word is now rare and mostly replaced by 許す.