I can’t think of any definition.
If someone keeps shabbos and kashrus, but not any other mitzva, is that frum?
If someone keeps shabbos, kashrus, nidda, yomtov, and wears teffilin; but, doesn’t daven, doesnt fast on any fast, doesn’t wear tzitzis, doesn’t have a bris, is married to a goy, steals from the government, steals from business partners, denies G-d, and doesnt keep any other mitzva, is that frum.
My point is, there is no list you can give which is all inclusive of what you need to do, and is all exclusive of things which can make you “frum” even if you don’t do all those things.