All articles A–Z

Intercalary month

An intercalary month is an extra month inserted into lunisolar calendars to keep lunar months aligned with the seasons, typically seven times in a 19-year Metonic cycle.

Intercalated cell of salivary gland

Intercalated duct cell: cuboidal epithelial cell lining the smallest salivary ducts between acini and striated ducts; markers K7, IP3R3, Cx26, TMEM16a, AQP5; secretory phenotype and progenitor role.

Intercalation (chemistry)

Intercalation is a reversible chemical reaction in which a guest species inserts into a layered host without major structural change; it underlies the lithium-ion battery's graphite anode.

Intercalation (timekeeping)

Intercalation, also known as calendrical intercalation, is the insertion of an extra day or month into a calendar, such as a leap day, to keep it aligned with the seasons.

Intercalation compound

An intercalation compound is a material formed when guest species such as ions are reversibly inserted into a crystalline host lattice; the mechanism underlies Li-ion battery electrodes.

Oct 22, 2026

Intercalation pseudocapacitance

Intercalation pseudocapacitance is a charge-storage mechanism in which ions insert into the bulk of an electrode at capacitor-like rates, named in 2013 from studies of lithium ions in niobium pentoxide.

Intercarrier interference cancellation

Intercarrier interference cancellation covers signal-processing techniques that suppress intercarrier interference in OFDM systems, where mobile reception, carrier frequency offset, or phase noise destroy subcarrier orthogonality.

Intercarrier interference self-cancellation

Intercarrier interference self-cancellation (ICI self-cancellation) is a signal-processing technique for OFDM systems, introduced by Zhao and Häggman in 2001, that spreads each data symbol over adjacent subcarriers so their interference cancels.

Oct 20, 2026

Intercellular adhesion molecule

Intercellular adhesion molecules (ICAM-1 to ICAM-5, e.g. CD54) are immunoglobulin-superfamily cell adhesion proteins that bind β2 integrins LFA-1 and Mac-1, mediate leukocyte trafficking, and serve as receptors for rhinoviruses and malaria parasites.

Sep 29, 2026

Intercept cross-lagged panel model

The intercept cross-lagged panel model (RI-CLPM) is a structural equation model proposed by Hamaker, Kuiper, and Grasman in 2015 that separates stable between-person differences from within-person lagged effects.

Intercept message

An intercept message is a recorded telephone announcement played to callers whose dialed number cannot be completed because it was changed, disconnected, or never assigned.

Sep 29, 2026

Intercept method

The intercept method, also called the Marcq Saint Hilaire method, is a celestial navigation technique that turns one altitude observation into a line of position.

Sep 29, 2026

Interceptive orthodontic treatment

Interceptive orthodontic treatment is the short-term correction of developing malocclusions and jaw discrepancies in children, redirecting growth in 9 to 15 months to reduce or avoid later treatment.

Interceptive Orthodontics

Interceptive orthodontics is the branch of orthodontics that treats a developing malocclusion during the primary or mixed dentition, typically starting no later than age 7, to simplify later care.

Interceptor (film)

Interceptor (2022) is an Australian action thriller on Netflix, Matthew Reilly's directorial debut co-written with Stuart Beattie, starring Elsa Pataky as Captain JJ Collins defending a Pacific missile interceptor base from Luke Bracey's mercenaries amid 16 stolen nuclear missiles; RT 47%, Metacritic 51.

Interceptor aircraft

An interceptor aircraft, also called an interceptor fighter, is a fighter built for speed and climb to intercept enemy aircraft, trading agility and range for the mission.

Interceptor drone

An interceptor drone is an unmanned aerial vehicle that flies toward a hostile drone and stops it in the air, most often with a net or by ramming.

Intercession

Intercession, also called intercessory prayer, is pleading with God by one with standing before him to obtain mercy for another, a doctrine shared by Christianity, where saints intercede, and Islam, where it is called shafāʿa.

Intercession of saints

The intercession of saints, also called prayer to saints, is the Christian doctrine, held by Catholic and Orthodox churches, that saints in heaven pray to God for people on earth.

Interchange (de Kooning)

Interchange, also titled Interchanged, is a 1955 painting by Willem de Kooning showing an abstracted seated woman in pink. Sold for $4,000 in 1955, $20.68 million in 1989, and $300 million to Kenneth Griffin in 2015.

Interchange (road)

An interchange is a grade-separated road junction where ramps connect highways that do not cross at grade, allowing traffic to merge and turn without signals.

Interchange instability

The interchange instability, also called the flute instability, is a magnetohydrodynamic instability in which plasma flux tubes exchange positions under pressure gradients and bad field-line curvature.

Interchange station

An interchange station is a passenger transport station where travelers transfer between modes, such as rail and bus, or between two services of the same mode.

Interchangeable parts

Interchangeable parts are standardized, identical components manufactured to a precise tolerance so any one can substitute for another without fitting or rework, first demonstrated in 1778.

Intercisa

Intercisa (Dunaújváros, Hungary): Roman auxiliary fort and vicus on the Pannonian limes, Danube left bank. Earth-and-timber fort late 1st century AD, stone fort 178-182, Syrian cohors I milliaria Hemesenorum from c. 180, occupied until the Hunnic cession of 433-434.