spliceosome /ˈsplaɪsioʊˌsoʊm/ noun1 •A dynamic complex of RNA and protein subunits that removes introns from precursor mRNA.This complex, termed a "spliceosome," is thought to contain components necessary for mRNA splicing; its existence can explain how separated exons on pre-mRNA are brought into contact. — 1985 formsspliceosomes