The Collaborative International Dictionary
Despumating
Despumate \Des"pu*mate\, v. t. & i. [imp. & p. p. Despumated; p. pr. & vb. n. Despumating.] [L. despumatus, p. p. of despumare to despume; de- + spumare to foam, froth, spuma froth, scum.] To throw off impurities in spume; to work off in foam or scum; to foam.
Wiktionary
despumating
vb. (present participle of despumate English)