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