soliton
n 1: (physics) a quantum of energy or quasiparticle that can be
propagated as a traveling wave in nonlinear systems and is
neither preceded nor followed by another such disturbance;
does not obey the superposition principle and does not
dissipate; "soliton waves can travel long distances with
little loss of energy or structure" [syn: {soliton},
{soliton wave}, {solitary wave}]