/ Dictionary / Index S siphonostele: Meaning and Definition of Find definitions for: si•phon•o•stele Pronunciation: (sī-fon'u-stēl", sī'fu-nu-stēl"), [key] — n. Bot. a hollow tube of vascular tissue enclosing a pith and embedded in ground tissue. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. siphonophore Siphrei Torah* Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language