With elements as「fluid of death, fluid flow unseen」the glyph may be referring to a flow of fluids of some sort, likely gonorrheal or diarrheal in nature, that cause EMBARRASSING PANIC due to the related odor if not in full view. May refer to a SUDDEN POST-MORTEM DISCHARGE OF FLUIDS from various orifices of a corpse as the sphincter muscles relax:「flow with death, fluids [normally] unseen.」A「flow unseen」also occurs during copulation within some sort of orifice [dead or alive], indistinct and unviewable for the moment.「Fluid flow of the dead, with the dead, unseen」suggests necrophilia, post-mortem ejaculation, and/or a female masturbating with the priapism of a corpse (yes, it happened...can't actually call that coitus, though).
「Observers at public hangings noted male victims developed an erection, sometimes remaining after death [priapism], and occasionally ejaculated when being hanged. Note that, however, ejaculation [also] occurs in hanging victims after death because of disseminated muscle relaxation. This is a different mechanism from that sought by autoerotic asphyxiation practitioners.」
[ https://en.wikipedia.org/wiki/Erotic_asphyxiation 2011-01-20 ]
「A death erection, angel lust, or terminal erection is a post-mortem erection, technically a priapism, observed in the corpses of men who have been executed, particularly by hanging. The phenomenon has been attributed to pressure on the cerebellum created by the noose. Spinal cord injuries are known to be associated with priapism. Injuries to the cerebellum or spinal cord are often associated with priapism in living patients. Death by hanging, whether an execution or a suicide, has been observed to affect the genitals of both men and women. In women, the labia and clitoris will become engorged and there may be a discharge of blood from the vagina. In men, 'a more or less complete state of erection of the penis, with discharge of urine, mucus or prostatic fluid is a frequent occurrence…present in one case in three.' Other causes of death may also result in these effects, including fatal gunshot wounds to the brain, damage to major blood vessels, and violent death by poisoning. A postmortem priapism is an indicator that death was likely swift and violent.」
[ https://en.wikipedia.org/wiki/Death_erection 2013-09-26 ]

External source definitions
...none located, and you ought to ask yourself, why not?
Definition speculated from combining the elements and from usage in other glyphs.