“Kunoichi,” the Japanese word for female ninja, literally translates as “nine and one” in reference to the female body having one more orifice than the male’s nine
“Ninja is an on’yomi (Early Middle Chinese-influenced) reading of the two kanji. In the native kun’yomi kanji reading, it is pronounced shinobi, a shortened form of the transcription shinobi-no-mono. These two systems of pronouncing kanji create words (ninja/ninsha or shinobi-no-mono) with similar meanings.
The word shinobi appears in the written record as far back as the late 8th century in poems in the Man’yōshū. The underlying connotation of shinobi means to steal away and — by extension — “”to forbear””, hence its association with stealth and invisibility. Mono means “”a person””. It also relates to the term shinobu, which means to hide.
Historically, the word ninja was not in common use, and a variety of regional colloquialisms evolved to describe what would later be dubbed ninja. Along with shinobi, some examples include monomi (“”one who sees””), nokizaru (“”macaque on the roof””), rappa (“”ruffian””), kusa (“”grass””) and Iga-mono (“”one from Iga””). In historical documents, shinobi is almost always used.
Kunoichi, meaning a female ninja, supposedly came from the characters くノ一 (pronounced ku, no and ichi), which make up the three strokes that form the kanji for “”woman”” . A popular etymology would derive the term from (talent) with Japanese numbers “”ku”” for “”nine””, the particle “”no”” for “”and”” and “”ichi”” for “”one””, literally translated to “”Nine and One””. The meaning for this name is derived from the number of orifices on a female body. A male has nine, a female has one more (the vaginal opening) and possesses the skills to make use of this orifice as well.
In the West, the word ninja became more prevalent than shinobi in the post-World War II culture, possibly because it was more comfortable for Western speakers. In English, the plural of ninja can be either unchanged as ninja, reflecting the Japanese language’s lack of grammatical number, or the regular English plural ninjas.”