As some scholars suggest, perhaps an「arrow with defective shaft」making use of the elements for「arrow, thrusting shaft」and meaning SHAFTING, ERROR, SLIP, MISS, yet one must wonder, why anyone would finish making an arrow with such a shaft or bother keeping it around if it later became warped, or attempt to actually lauch it from an archery bow? replacement for an older glyph meaning「merciless」having elements of「army dog erection in orifice of the king」(戜) perhaps in reference to a conquering invader's abuse of a local dignitary, LOSING control due to a SHAFTING ERROR while publicly SLIPPING (see related glyphs). Perhaps refers to what will happen if we LOSE or COMMIT AN ERROR.
Armies invading China were referred to as「the dogs.」Note that humans have not changed too much, and this behavior is still exhibited today by human beings during war:「Beginning in 2004, human rights violations in the form of physical, psychological, and sexual abuse, including torture, reports of rape, sodomy, and homicide of prisoners held in the Abu Ghraib prison in Iraq (also known as Baghdad Correctional Facility) came to public attention. These acts were committed by military police personnel of the United States Army together with additional US governmental agencies.」
[ https://en.wikipedia.org/wiki/Abu_Ghraib_torture_and_prisoner_abuse 2012-07-02 ]
And in most cases, the「head of an adult man」can be related to all varieties of FAULTS, LOSSES, SLIPS, and ERRORS.
The modern glyph resembles the modern form of「arrow」and presumably also depicts a defective arrow…compare「horse」(old version: 午) with「cattle」(牛) and the only difference is a hump on the back of cattle or the reciprocating motion of a slippery pestle, indicating the higher shoulders and sometimes humps on the shoulders of brahmans, yaks, and water buffalo…such a hump located along an arrow's shaft will certainly cause it to be fired astray as the bump crosses the bow, or distort the aerodynamics, causing a SLIP, ERROR, LOSS, MISS. Perhaps depicting so-called「friendly fire」by hitting one of your own side with an arrow. Could also be an「arrow shot straight up, vertically」to mean one MISTAKENLY shot in ERROR that SLIPPED. Note that straight up firing of arrows often leads to them falling straight down upon the same archers, leading to a possible LOSS of an archer and/ or the arrow. Big lumps or bumps on any sort of shaft might be cause for some further investigation of an ERROR, LOSS, MISS, FAULT in the past.
Although the present stroke pattern is drawn differently, glyph includes「the need to inform」(⺧) or「chattel, herd meat」with「person.」…both somewhat analogous to 知 (「head of male shaft penetrating an orifice」) and informing someone beforehand about a continuing slippery fishy condition caused by a prior MISTAKE, getting an unwanted dose of the booby prize known unaffectionately as the clap. Same explanation applies to elements as the「head of one's rod in heaven.」

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: to lose; to miss; to fail
Japanese EDRDG: lose, error, fault, disadvantage, loss
Unihan extended: lose; make mistake, neglect