Debakame (出歯亀) is a Japanese word that originally meant "peeping Tom and murderer" but now generally just means "peeping Tom" when used at all. The etymology is simple: in 1908, a known pepping Tom named IKEDA Kametarō (池田亀太郎), a.k.a. Deba no Kamekichi (出歯の亀吉; "Bucktooth Kammo", in Australian translation), was arrested for and found guilty of murdering a woman on her way back from the public baths. (See Wikipedia for discussion of his possible innocence, and an aside noting that it is not a crime to use infra-red imaging to watch people having sex outdoors at night. Stay classy, Wikipedia!)

MORI Ōgai mentions him in Vita Sexualis:

そのうちに出歯亀（でばかめ）事件というのが現われた。出歯亀という職人が不断女湯を覗く癖があって、あるとき湯から帰る女の跡を附けて行って、暴行を加えたのである。 [...] それが一時世間の大問題に膨脹（ぼうちょう）する。所謂（いわゆる）自然主義と聯絡（れんらく）を附けられる。出歯亀主義という自然主義の別名が出来る。出歯るという動詞が出来て流行する。

At around this time the Debakame Incident occurred. There was a worker named Debakame who had a habit of peeping in on the women's baths, and one day he followed a woman home from the baths and assaulted her. [...] This incident grew into a huge public issue for a time. Connections were made to the Naturalist movement in literature. Some even took to calling Naturalism "Debakame-ism." The verb debaru [出歯る] was coined and became popular for a while.

Having read my share of Naturalist novels in the original, it is almost unbelievable to me that they should be accused of being too stimulating, but there you have it.

Note that debaru follows exactly the same pattern as celebrated/reviled modern coinages makuru (go to McDonalds), takuru (take a taxi), etc. (Presumably Mori was aware of and is not confusing it with the other debaru, 出張る, meaning "stick out".)