noun
: the structure typical of a cyclic chemical compound and consisting of one or more rings (as fused rings)
five- and six-membered ring systems
— compare skeleton
noun
: the structure typical of a cyclic chemical compound and consisting of one or more rings (as fused rings)
five- and six-membered ring systems
— compare skeleton
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012