ˈpen.ˌtōs also -ōz noun
( -s )
Etymology: International Scientific Vocabulary penta- + -ose
: any of a class of monosaccharides C 5 H 10 O 5 (as xylose or ribulose) containing five carbon atoms in the molecule that are obtained especially from pentosans, nucleic acids, or nucleosides by hydrolysis or from hexoses by degradation — compare deoxypentose , methylpentose