In Chinese, formerly「reaming」with a「diseased and spewing penis」as it referred to a medical procedure extant in the good ol' days of removing infection pus using a bougie from a sexually transmitted disease that was CONCEALED ON THE INSIDE and causing pecker rot and stench—obviously meaning ENDURANCE, PATIENCE, SELF-RESTRAINT before and during the procedure, CONCEAL, HIDDEN, STEALTH, SNEAKY afterwards to protect one's reputation.
　「Emphasis on erection in no-longer-integrated foot spewing drops」was CONCEALED ON THE INSIDE of the service provider's foot or both feet that likely demanded her ENDURANCE, PATIENCE, SELF-RESTRAINT…what a life, eh?
　Moreover, CONCEALED ON THE UNDERSIDE relates to small, round, reddish-brown bumps covering the underside of the penile shaft as a symptom of syphilis due to screwing with ewe, STEALTHILY HIDDEN and the sufferer SNEAKY about it.
　Perhaps「blade-hearted」meaning NINJA is a purely Japanese meaning, as is a reference to FERN LEAVES and colored lumps hidden on the underside of a skin surface or within clothing: ferns reproduce via sporogenesis occurring in sporangia that are small, round, reddish-brown bumps covering the underside of the leaves. While not closely related to most ninja, sporangia do resemble syphilitic chancre spots on human skin, pox pustules filled with spirochetes awaiting transmission to a new host…FERN in Chinese (荵) elements literally are「emerging shafts, tense erection severed with gasping due to penile disease.」Dryopteris marginalis fern spores on the underside of leaves burst open and discharge when ripe, a process known as sporangial dehiscence, the splitting of the sporangial capsule and the discharge of spores.
　「Erection force reaming and spurting drops from penis」as HAIR ORNAMENTATIONS that are deliberately concealed.

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: to bear; to endure; to tolerate; to restrain oneself
Japanese: Davallia mariesii, Lepisorus thunbergiana, color of clothing layers under one's overcoat, ancient women's hairstyle, clothing patterned using the fern Davallia mariesii, endurance, forbearance, patience, self-restraint, stealth, travelling incognito, ninjutsu, ninja, sneak theft, sneak thief, tolerance, to conceal oneself, to hide, to endure, stealthy, secret
Unihan extended: endure, bear, suffer; forbear
EDRDG: endure; bear; put up with; conceal; secrete; spy; sneak

Used within names (nanori)
おし