insanitary

in- +‎ sanitary

insanitary (comparative more insanitary, superlative most insanitary)

1. Of or pertaining to a lack of sanitation; unsanitary, dirty, unhealthy.
   • 1892 May 14, The Lancet, page 1089:

     The important duty of getting rid of uninhabitable houses or insanitary property devolves on the sanitary authority, and requires to be carried out with discrimination.

   • 2014, Lee Jackson, Dirty Old London: The Victorian Fight Against Filth, page 17:

     The insanitary house displayed poor heating and plumbing, arsenical wallpaper and, in the basement area at the front of the house, 'a large wooden dustbin, placed as is frequently the case, where its malodorous and often dangerous contents must be a constant nuisance on the premises'.

   • 2015, Leona J. Skelton, Sanitation in Urban Britain, 1560–1700:

     Within the minority of nuisance fines for which the ward was recorded, however, there was a striking degree of symmetry across the wards, a difference of only eighteen between the ward with the most insanitary nuisances, Monk Ward, and that with the fewest, Micklegate Ward.

American English currently prefers the variation unsanitary.