Black's Law Dictionary (2nd edition)dictionaries

Jus Ad Rem

A term of the clvll law, meaning “a right to a thing;” that is, a right exercisable by one person over a particular article of property in virtue of a coutract or obligatlon incurred by another person in re-spect to lt, and whlch is enforceable only against or through such other person. It is thus distinguished from jns in re, which is a complete aud absolute dominion over a thing available against all persons

Source: Black's Law Dictionary 2nd Ed (1910)