The Collaborative International Dictionary of English v.0.48:

Equimomental \E`qui*mo*men"tal\, a. [Equi- + momental.] (Mech.)
   Having equal moments of inertia.
   [1913 Webster]

   Note: Two bodies or systems of bodies are said to be
         equimomental when their moments of inertia about all
         straight lines are equal each to each.
         [1913 Webster]

   Equimomental cone of a given rigid body, a conical surface
      that has any given vertex, and is described by a straight
      line which moves in such manner that the moment of inertia
      of the given rigid body about the line is in all its
      positions the same.
      [1913 Webster]