The Collaborative International Dictionary
Spongoblast
Spongoblast \Spon"go*blast\ (sp[o^][ng]"g[-o]*bl[a^]st), n. [Gr. spo`ggos sponge + -blast.] (Zo["o]l.) One of the cells which, in sponges, secrete the spongin, or the material of the horny fibers.
Wiktionary
spongoblast
n. (context zoology English) In sponges, one of the cells that secrete spongin.