\Me"um\, n. [L., neut. of meus mine.]
Lit., mine; that which is mine; -- used in the phrase meum et
tuum, or meum and tuum; as, to confound meum and tuum, to
fail to distinguish one's own property from that of others;
to be dishonest.
      Ancestors . . . generally esteemed more renowned for
      ancient family and high courage than for accurately
      regarding the trifling distinction of meum and tuum.
                                               --Sir W.
                                               Scott.