hy·pox·i·a 
(hī-pŏksē-ə, hĭ-)
(hī-pŏksē-ə, hĭ-)n.
1. Deficiency in the amount of oxygen reaching body tissues.
2. Depletion of dissolved oxygen in aquatic environments to levels that are detrimental or fatal to aerobic organisms, often caused by eutrophication.
hy·poxic adj.