[frum | frim]), from the German fromm, meaning “” or “pious”, is a Yiddish word meaning committed to be observant of the 613 Mitzvot, or Jewish commandments, specifically of Orthodox Judaism. …
The word “frum” can have other specific meanings depending on the context in which it is used. Often the terms frum and frei indicate one’s social associations as much as his/her actual religious commitment.
taken from wikipedia…:) feel free to google as well