All articles A–Z

Supposition theory

Supposition theory (suppositio) is the medieval logic doctrine of what a term stands for in a proposition, distinct from signification. Modes include material, simple, and personal supposition; it dominated semantics for over 500 years.

Suppository

Suppository: solid single-dose medication inserted rectally, vaginally, or urethrally; melts or dissolves to release drug locally or systemically, partially bypassing liver first-pass metabolism; fatty or hydrophilic bases.

Suppressed lactation

Suppressed lactation: deliberate prevention or cessation of milk production after childbirth in non-breastfeeding women, also called lactation inhibition. Managed physiologically (breast support, comfort expression) or with drugs such as bromocriptine and cabergoline; distinct from agalactia (JB46.3).

Sep 19, 2026

Suppression of Amenhotep

The suppression of Amenhotep, also called the War of the High Priest, was the removal of the High Priest of Amun from office at Thebes for about eight months, around 1089–1088 BC.

Suppression of apoptosis

Suppression of apoptosis (Reactome R-HSA-9635465) is the inhibition of programmed cell death, mainly via anti-apoptotic BCL-2 family proteins and IAPs; it underlies cancer immune evasion and is reversed therapeutically by venetoclax.

Suppression of Enemy Air Defenses

Suppression of Enemy Air Defenses (SEAD) is a military mission that neutralizes, destroys, or degrades enemy air defenses, distinct from the permanent destruction of DEAD.

Sep 24, 2026

Suppression of Mazdakism

The Suppression of Mazdakism (قتل عام مزدکیان) was the destruction of the Mazdakite movement in the Sasanian Empire, centered on a massacre at Ctesiphon about 528.

Suppression of the Society of Jesus

Suppression of the Society of Jesus: the 1759–1767 national expulsions from Portugal, France, and Spain, Clement XIV's brief Dominus ac Redemptor abolishing the Jesuits in 1773, and Pius VII's 1814 restoration.

Suppressive antiretroviral therapy

Suppressive antiretroviral therapy (ART) is the combination of antiretroviral drugs that keeps a person's HIV viral load undetectable, halting disease progression and preventing sexual transmission of the virus.

Suppressive fire

Suppressive fire, also called covering fire, is fire directed at enemy personnel, weapons, or positions to degrade their performance rather than destroy them, enabling friendly movement.

Oct 15, 2026

Suppressor (firearms)

A suppressor, also called a silencer or sound moderator, is a muzzle device that cuts gunshot noise by about 3 to 35 dB, though the shot stays audible.

Suppressor Genes

Suppressor genes are genes carrying a suppressor allele or mutation that cancels the effect of a previous mutation, restoring the wild-type phenotype; distinct from tumor suppressor genes.

Suppressor of fused

Suppressor of fused (SUFU, Sufu) is a conserved negative regulator of Hedgehog signaling that sequesters GLI1-3 transcription factors in the cytoplasm; discovered in Drosophila as a fused suppressor, essential in mouse development, a tumor suppressor linked to medulloblastoma.

Suprabasal cell

Suprabasal cell: epithelial cell in layers above the basal layer of stratified or pseudostratified epithelia (skin, esophagus, airway, cornea); arises from basal cells, expresses differentiation keratins, and is committed to terminal differentiation.

Supracervical hysterectomy

Supracervical hysterectomy is an operation that removes the uterine corpus while leaving the cervix in place, used mainly for benign disorders such as fibroids and abnormal bleeding.

Suprachiasmatic nucleus

Suprachiasmatic nucleus (SCN), hypothalamic master circadian pacemaker above the optic chiasm, ~20,000 neurons, intrinsic period ~24.2 h, light-entrained via the retinohypothalamic tract, synchronizes peripheral clocks and melatonin rhythms.

Supraclavicular brachial plexus block

The supraclavicular brachial plexus block, or supraclavicular block, is a regional anesthesia technique injecting local anesthetic above the clavicle to numb the arm and shoulder.

Supraclavicular lymph nodes

Supraclavicular lymph nodes (nodi lymphoidei supraclaviculares): 4-12 nodes above the clavicle draining breast, lung, esophagus, and abdomen; the left Virchow node (Troisier sign) signals metastatic cancer in 54-85% of enlargements.

Supracondylar fracture of humerus

Supracondylar humerus fracture, pediatric distal humerus fracture above the elbow, most common childhood elbow injury, Gartland types I-IV, treated by casting or closed reduction with percutaneous pinning.

Supraglacial lake

Supraglacial lakes are meltwater ponds on glacier and ice-sheet surfaces in Greenland and Antarctica. They store runoff, drain by hydrofracture or overflow, modulate ice flow, and can trigger ice-shelf breakup.

Supraglottoplasty

Supraglottoplasty is a surgical procedure in otolaryngology that removes or reduces abnormal supraglottic laryngeal tissue to relieve the airway obstruction caused by laryngomalacia, the most common cause of stridor in infants.

Supramalleolar osteotomy

Supramalleolar osteotomy is a joint-preserving orthopedic procedure that cuts and realigns the tibia just above the ankle to shift load onto preserved cartilage in asymmetric ankle arthritis.

Oct 15, 2026

Supramolecular polymer

A supramolecular polymer is a polymeric array of monomeric units held together by reversible noncovalent interactions like hydrogen bonding, first proposed by Jean-Marie Lehn in 1990.

Oct 15, 2026

Supramolecular polymerization

Supramolecular polymerization is the reversible assembly of monomers into polymeric arrays through directional noncovalent interactions such as hydrogen bonds and metal coordination, giving stimuli-responsive, self-healing materials.

Oct 22, 2026

Supramolecular tandem assay

A supramolecular tandem assay is a label-free method for monitoring enzyme activity in real time, using a macrocyclic host and fluorescent dye whose displacement reports the enzymatic conversion.

Supranational union

Supranational union: an organization of states with common institutions whose binding decisions apply directly in members, as in the EU; contrasted with intergovernmental bodies like ASEAN and hybrid cases like the African Union.

Suprapubic cystostomy

Suprapubic cystostomy is a urological procedure that places a catheter through the lower abdominal wall into the bladder to drain urine, used when urethral catheterization is not possible.

Suprascapular nerve block

A suprascapular nerve block (SSNB) is a regional anesthesia procedure injecting local anesthetic near the suprascapular nerve, which carries about 70% of shoulder sensation, to relieve shoulder pain.

Supraspinatus muscle

Supraspinatus muscle: rotator cuff muscle of the shoulder, originating in the supraspinous fossa of the scapula and inserting on the greater tubercle of the humerus; initiates 0-15 degrees of arm abduction, innervated by the suprascapular nerve (C5, C6), and the cuff tendon most prone to tears.