Synonyms for Septic:

adj.

harmful (adjective)
poisonous.
inflamed (adjective)
festering, infected.
pestilential (adjective)
pestilent.
poison/poisonous (adjective)
malignant, noxious, deadly, toxic, infective.
unhealthful (adjective)
unwholesome.
unhealthy (adjective)
insalubrious, unwholesome, toxic, pestilent, gangrenous, infected, contagious, deadly, noxious, contaminated, unsanitary, unhygienic, pathological, unhealthy, poisonous, malignant, diseased.
unwholesome (adjective)
insalubrious, rotten, poisonous, contaminated.
virulent (adjective)
unhealthy, unwholesome.

n.

contagion, defense mechanism, antibody, defense, carrier, candida, cross-contamination, cross infection, fester, biosecurity. unsanitary (noun)
rotten.

Other synonyms:

adj.
insalubrious, toxic.