The Collaborative International Dictionary of English v.0.48:

Anaerobia \An*a`["e]r*o"bi*a\, Anaerobes \An"aer*obes\,
Anaerobes \An*a"["e]r*obes\, n. pl. [NL. anaerobia; an-not +
   a["e]ro- + Gr.? life.] (Bacteriol.)
   Ana["e]robic bacteria. They are called facultative
   ana["e]robes when able to live either in the presence or
   absence of free oxygen; obligate ana["e]robes, or
   obligatory ana["e]robes, when they thrive only in its
   absence.
   [Webster 1913 Suppl.]