In Chinese refers to「two connected orifices」such as those located at each end of the alimentary canal, or juxtaposed in a female groin, or facing one another naturally from two groins. In particular the mouth and anus, one at each end of the SPINE, are both used to TOOT or make similar LOW TONAL SOUNDS, such as passing flatulence or moaning. Vaginas queef at times in a similar manner, especially after the thighs have been spread wide open such as might occur when two were making that sort of connection, or perhaps while bathing.
In Japanese,「connected orifices」as a BACKBONE, SPINE with the spinal cord of essential nerves inside bone「orifices.」One's BACK. It can be argued that the SPINE and central nervous system connect a human mouth with the fundament as the bone「structure between these two orifices」and that the alimentary canal also connects the human mouth with the fundament as two different orifices on each end, although remaining separate orifices for most folks, literally if not figuratively: some folks do at times「talk out of one's ass」and exaggerate, or speak authoritatively on a subject while actually knowing little, and others suffer from severe halitosis, hence these orifices share some characteristics. Japanese references to bathing that include this glyph are perhaps denoting those two「connected orifices」require regular cleansing, connected by the perineum.
Notably, this glyph was replaced in some modernized glyphs by「arch, sole of the foot」(弓) as it was in dynastic China too, when naturally occurring orifices were replaced by surrogate orifices in the soles of feet. As depicted in erotic Chinese art, men in dynastic China masturbated by wrapping no-longer-integrated feet around an erect penis:「Bound feet were once considered intensely erotic in Chinese culture. …The process was started before the arch of the foot had a chance to develop fully, usually between the ages of 2 and 5. …Qing Dynasty sex manuals listed 48 different ways of playing with women's [no-longer-integrated] bound feet」(after removing the binding cloths, of course)
[ https://en.wikipedia.org/wiki/Foot_binding 2012-12-17 ]

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: pitchpipe, pitch standard, one of the twelve semitones in the traditional tone system
Japanese EDRDG: spine, backbone
Unihan extended: surname; a musical note

Used within names (nanori)
とも　･　なが