Definition of iridaceous in US English:

iridaceous

adjective

Botany
  • Relating to or denoting plants of the iris family (Iridaceae), which grow from bulbs, corms, or rhizomes.

Origin

Mid 19th century: from modern Latin Iridaceae (plural), based on Greek iris, irid- ‘rainbow’, + -ous.

Pronunciation

iridaceous

/ˌirəˈdāSHəs/