Devoutly observant of Jewish laws; strictly orthodox or religious.
Origin
Mid 19th century; earliest use found in Arthur Munby (1828–1910), diarist and civil servant. From Yiddish frum from Middle High German vrum, vrom pious, devout (German fromm; in Old High German only as noun fruma, froma advantage, benefit) from an ablaut variant of the same Germanic base as Old English fram bold, brave, strong, eager.