The Collaborative International Dictionary of English v.0.48:

Pansclavic \Pan`sclav"ic\, Pansclavism \Pan`sclav"ism\,
Pansclavist \Pan`sclav"ist\, Pansclavonian \Pan`scla*vo"ni*an\
   See Panslavic, Panslavism, etc.
   [1913 Webster]