Main Entry: rhi·zo·bi·um

Pronunciation: \rī-ˈzō-bē-əm\

Function: noun

Inflected Form(s): plural -bia\-bē-ə\

Etymology: New Latin, from rhiz- + Greek bios life — more at quick

Date: 1921

: any of a genus (Rhizobium) of small heterotrophic soil bacteria capable of forming symbiotic nodules on the roots of leguminous plants and of there becoming bacteroids that fix atmospheric nitrogen

— rhi·zo·bi·al \-bē-əl\ adjective