Proto-Japanese: *situ
Meaning: damp place, dampness
Russian meaning: влажность, влажное место
Middle Japanese: situ
Tokyo: shitsu
Comments: The word is usually considered to be an on-reading of the Chinese character 濕 MC śip. The latter should normally have a reading MJ sifu, mod. shū (which exists), while situ/shitsu, attested in separate usage since Middle Japanese, appears quite irregular phonetically for a Chinese loan. We should rather think of a genuine *situ, misconceived as a Chinese loanword.