All articles A–Z

Intermediate frequency

An intermediate frequency (IF) is a fixed frequency to which a received radio signal is shifted by mixing, the core of the superheterodyne receiver Edwin Armstrong developed in 1918.

Intermediate generalized junctional epidermolysis bullosa

Intermediate generalized junctional epidermolysis bullosa, formerly called JEB mitis or non-Herlitz JEB, is a non-lethal autosomal recessive skin-fragility disorder with blistering from birth that usually improves.

Oct 10, 2026

Intermediate good

An intermediate good is a produced good sold to be used up or transformed in making other goods, and its value is excluded from GDP to avoid double counting.

Intermediate growth

Intermediate growth is the property of a finitely generated group growing faster than any polynomial but slower than any exponential, first constructed by Rostislav Grigorchuk in 1983.

Intermediate logic

An intermediate logic, also called a superintuitionistic logic, is a consistent set of propositional formulas containing intuitionistic propositional calculus and contained in classical logic; Gödel showed in 1932 that infinitely many exist.

Intermediate osteopetrosis

Intermediate osteopetrosis (ORPHA:210110, intermediate autosomal osteopetrosis, IAO) is a rare genetic bone dysplasia with dense, fracture-prone bones, anemia, and sandwich vertebra radiographs, onset in childhood, genes CLCN7, PLEKHM1, TCIRG1, treated supportively.

Intermediate polar

An intermediate polar, also called a DQ Herculis star, is a cataclysmic variable in which a magnetic white dwarf accretes from a companion while spinning faster than the orbit.

Intermediate uveitis

Intermediate uveitis, also known as pars planitis, is an eye inflammation centered in the vitreous, marked by floaters, blurred vision, and snowbank or snowball formations.

Intermediate value theorem

The intermediate value theorem, also known as Bolzano's theorem or the Cauchy–Bolzano theorem, states that a continuous real function on a closed interval takes every value between its endpoint values.

Intermediate-level waste

Intermediate-level waste (ILW) is a class of radioactive waste requiring greater containment than near-surface disposal allows, with little decay heat, arising mainly from spent fuel reprocessing and reactor decommissioning.

Intermediate-mass black hole

An intermediate-mass black hole (IMBH) is a black hole of roughly 100 to 100,000 solar masses, between stellar-mass and supermassive black holes; candidates remain debated, with GW190521 the strongest evidence.

Intermediate-range ballistic missile

An intermediate-range ballistic missile (IRBM) is a ballistic missile with a range of 3,000 to 5,500 kilometers, between medium-range and intercontinental missiles; ground-launched IRBMs were banned by the 1987 INF Treaty.

Intermediate-Range Nuclear Forces Treaty (Договор о ликвидации ракет средней и меньшей дальности)

The Intermediate-Range Nuclear Forces (INF) Treaty, signed by Reagan and Gorbachev on December 8, 1987, banned U.S. and Soviet ground-launched ballistic and cruise missiles of 500 to 5,500 km, eliminated 2,692 missiles by 1991, and ended August 2, 2019 after U.S. withdrawal over Russia's 9M729 missile.

Intermenstrual bleeding

Intermenstrual bleeding (IMB, formerly metrorrhagia): uterine bleeding between regular menstrual periods, ICD-11 GA20.20. Causes include hormonal imbalance, IUDs, polyps, fibroids, infection, pregnancy complications, and cancer.

Intermetallic compound

An intermetallic compound is a solid compound of two or more metallic elements at fixed stoichiometric ratios, with an ordered crystal structure unlike either constituent metal.

Intermetallics (journal)

Intermetallics is a monthly peer-reviewed scientific journal published by Elsevier covering the science and engineering of intermetallic compounds, metallic glasses, and high-entropy alloys, founded in 1993 in Barking, England.

Intermezzo (novel)

Intermezzo (2024) is Sally Rooney's fourth novel, about Dublin brothers Peter, a 32-year-old barrister, and Ivan, a 22-year-old chess player, grieving their father while navigating age-gap romances; published by Faber & Faber.

Intermission (film)

Intermission (2003) is an Irish ensemble black comedy-drama, John Crowley's feature debut, written by Mark O'Rowe, starring Colin Farrell, Cillian Murphy, Kelly Macdonald, Shirley Henderson and Colm Meaney; a Dublin breakup triggers interlinked crime and romance stories.

Intermittency

Intermittency is a behavior in nonlinear dynamics where long laminar, nearly periodic phases are interrupted by chaotic bursts, described by Pomeau and Manneville in 1980.

Oct 20, 2026

Intermittent angle-closure

Intermittent angle-closure is a clinical form of primary angle-closure disease causing repeated, self-resolving episodes of blurred vision, haloes, and mild pain, which can progress to glaucoma if unrecognized.

Sep 29, 2026

Intermittent auscultation

Intermittent auscultation is a method of fetal monitoring during labor that listens to the fetal heart rate at set intervals with a Pinard stethoscope or handheld Doppler.

Intermittent claudication

Intermittent claudication, also called claudicatio intermittens, is exercise-induced leg pain relieved by rest and the most common symptom of peripheral artery disease; treated with supervised exercise, cilostazol, and selective revascularization.

Intermittent explosive disorder

Intermittent explosive disorder (IED), a DSM-5 disruptive, impulse-control disorder, features recurrent impulsive aggressive outbursts disproportionate to provocation; US lifetime prevalence 5.4–7.3%, onset in adolescence, treated with CBT and fluoxetine.

Intermittent fasting

Intermittent fasting, also called intermittent energy or calorie restriction, alternates fasting and eating periods, with time-restricted eating, alternate-day fasting, and the 5:2 diet as its main forms.

Intermittent gear

An intermittent gear, also called a partial or mutilated gear (間欠歯車), is a gear with teeth cut around only part of its circumference, so the output rotates and then dwells.

Intermittent hydrarthrosis

Intermittent hydrarthrosis, or periodic synoviosis, is a rare rheumatologic disease of recurrent, self-remitting knee effusions with fixed periodicity, absent systemic symptoms, no joint damage, and a subset linked to MEFV autoinflammatory mutations.

Sep 29, 2026

Intermittent mandatory ventilation

Intermittent mandatory ventilation (IMV) is a ventilator mode delivering mandatory breaths at a set rate while the patient breathes spontaneously between them, used for weaning.

Sep 29, 2026

Intermittent pneumatic compression

Intermittent pneumatic compression (IPC) is a treatment in which inflatable leg cuffs rhythmically inflate and deflate to squeeze blood from deep veins, used mainly to prevent venous thromboembolism in hospitalized and surgical patients.