What is the meaning of Antisymmetric?

Having the property that, for any two distinct elements of S, at least one is not related to the other via R; equivalently, having the property that, for any x, yS, if both xRy and yRx then x=y.

Whose sign changes on the application of a matrix transpose or some generalisation thereof:

  1. Whose transpose equals its negative (i.e., M = −M);
  2. That changes sign when any two indices are interchanged (e.g., Tijk = -Tjik);
  3. For which B(w,v) = -B(v,w).

Whose transpose equals its negative (i.e., M = −M);

That changes sign when any two indices are interchanged (e.g., Tijk = -Tjik);

For which B(w,v) = -B(v,w).

Source: wiktionary.org