d.s.p.m.

D.s.p.m. adds one letter to d.s.p. to say that the person left no sons, though daughters may have survived. The distinction mattered where land or a title passed through the male line.

You meet it mostly in English pedigrees and genealogies of colonial families with landed estates. When you see it, look for daughters' marriages, because the property often passed to them or their husbands.