altisonant

from The Collaborative International Dictionary of English v.0.48

Altisonant \Al*tis"o*nant\ ([a^]l*t[i^]s"[-o]*nant), a. [L.
   altus high + sonans, p. pr. of sonare to sound.]
   High-sounding; lofty or pompous. --Skelton.
   [1913 Webster]