Compounds in which every silicon atom is linked to three oxygen atoms and every oxygen
atom is linked to two silicon atoms, and having the general formula
(SiH)2nO3n.
By extension
hydrocarbyl derivatives are commonly included.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1366