ob. (abbreviation) obit, deceased, OB (abbreviation) order book, as in court order book. obiit. (abbreviation) he or she died. obit. (abbreviation) obituary. octoroon child of a quadroon; person having one-eighth black ancestry. of color black, Indian, persons of mixed blood. Old Dominion Virginia. old style calendar Julian calendar, used before the Gregorian calendar. olographic will an olographic or holographic will is handwritten and signed by the individual that the will belongs to. oral history an oral history is a collection of family stories told by a member of the family or by a close family friend. Normally, an oral history is transcribed onto paper, or is video or tape recorded. Oral histories can yield some of the best information about a family -- the kinds of things that you won't find written in records. oral will nuncupative will - oral will declared or dictated by the testator in his last sickness before a sufficient number of witnesses and afterwards put in writing. orphan a child whose mother, father, or both have died. orphan assylum an orphanage. OS old style calendar.