The Collaborative International Dictionary of English v.0.48:

Thermomagnetism \Ther`mo*mag"net*ism\
   (th[~e]r"m[-o]*m[a^]g"n[e^]t*[i^]z'm), n. [Thermo- +
   magnetism.]
   Magnetism as affected or caused by the action of heat; the
   relation of heat to magnetism.
   [1913 Webster]