What does diapyesis mean?
Diapyesis is a medical noun denoting the formation or discharge of pus — in other words, suppuration. It derives from Greek elements meaning essentially 'to make pus through,' combining the prefix dia- ('through' or 'thoroughly') with pyon ('pus'), the same root seen in pyogenic and empyema. The word belongs to the formal register of medicine and appears most often in older textbooks, surgical case notes, and pathological descriptions, where it signals that a wound or body cavity has become infected and is producing purulent material. A clinician might once have recorded diapyesis at an incision site as objective evidence of infection requiring drainage. Today the term has largely fallen out of everyday clinical speech, supplanted by plainer terms such as suppuration, purulence, or simply 'pus,' but it survives in historical medical writing and as a striking example of Greek-derived anatomical vocabulary. It should not be confused with the similar-sounding diapedesis, which refers to the movement of blood cells through vessel walls rather than to pus formation. For readers interested in the history of medicine, diapyesis offers a compact glimpse of how classical Greek roots shaped the language of pathology.
nounThe formation or discharge of pus; suppuration.
- The formation or discharge of pus in tissue; suppuration.
"The physician noted diapyesis at the site of the old incision, a sign that infection had set in."
"Persistent diapyesis prompted the surgeon to reopen and drain the wound."
"In nineteenth-century case notes, diapyesis was routinely recorded as evidence of deep-seated infection."
Regular -is → -es plural following Greek-derived nouns such as diagnosis and prognosis; rare because the word itself is uncommon.
"The pathologist's report documented multiple diapyeses across the affected tissue."
From an ancient Greek word for pus, diapyesis is the kind of term doctors once used to describe infection with clinical detachment — and it still sounds exactly as unpleasant as it means.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of diapyesis
Diapyesis comes from Greek, formed from dia- ('through' or 'throughout') combined with pyon ('pus') and a verbal suffix relating to making or producing, so it literally conveys 'a making of pus throughout.' The same Greek root py- gives English several other medical terms, including pyogenic (pus-producing), empyema (pus in a body cavity), and pyorrhea. The word entered scientific Latin before being adopted into English medical vocabulary, where it remained in use into the modern era before giving way to simpler Latinate alternatives like suppuration.
Related word forms
How diapyesis is actually used
A technical, chiefly historical medical term found mostly in older clinical literature; modern practice more often uses suppuration or describes pus directly. Rarely encountered outside medical contexts.
Easily confused with diapyesis
Diapedesis is the passage of blood cells through intact vessel walls, whereas diapyesis is the formation or discharge of pus.