Antonyms of adj hygienic

1 sense of hygienic

Sense 1
hygienic, hygienical -- (tending to promote or preserve health; "hygienic habits like using disposable tissues"; "hygienic surroundings with plenty of fresh air")

INDIRECT (VIA sanitary) -> unsanitary, insanitary, unhealthful -- (not sanitary or healthful; "unsanitary open sewers"; "grim and unsanitary conditions")

Similarity of adj hygienic

1 sense of hygienic

Sense 1
hygienic, hygienical -- (tending to promote or preserve health; "hygienic habits like using disposable tissues"; "hygienic surroundings with plenty of fresh air")
       => sanitary (vs. unsanitary), healthful -- (free from filth and pathogens; "sanitary conditions for preparing food"; "a sanitary washroom")