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