Definition of Monadelphia in US English:

Monadelphia

noun

Botany
historical
  • In the Linnaean artificial system: the sixteenth class of plants, comprising those with hermaphrodite flowers having the stamens united by their filaments below to form one set or tube.

Origin

Mid 18th century; earliest use found in Chambers's Cyclopaedia. From scientific Latin Monadelphia, former class name (Linnaeus Systema Naturae) from mono- + -adelphia.

Pronunciation

Monadelphia

/ˌmɒnəˈdɛlfɪə/