plas·mon 
(plăzmŏn′)
(plăzmŏn′)n.
1. The aggregate of cytoplasmic or extranuclear genetic material in an organism.
2. A quantum of collective electron oscillation in a metal, considered as a quasiparticle and analogous to the oscillations of a plasma consisting of stationary positive ions and a gas of electrons.
[German, from New Latin plasma, plasma; see PLASMA.]