(1) Of, pertaining to, having, or requiring the presence of air or free oxygen.
(2) (biology) Requiring air or oxygen for life or survival, used especially to refer to aerobic bacteria.
(3) (physiology) Pertaining to respiration occurring in the presence of oxygen, as aerobic respiration.
Word origin: Greek aero- "air" + bios "life".
Related forms: aerobically (adverb), aerobe (noun)