septic

Concise Oxford English Dictionary © 2008 Oxford University Press:
septic /ˈsɛptɪk/

▶adjective

• 1 (of a wound or a part of the body) infected with bacteria.

• 2 denoting a drainage system incorporating a septic tank.

– derivatives
septically adverb,
septicity /-ˈtɪsɪti/ noun.

– origin C17: via L. from Gk sēptikos, from sēpein ‘make rotten’.