IV may refer to:

Businesses and organizations

Immigration Voice Immigration Voice is a 501(c)(4) nonprofit organization that claims to work to alleviate problems faced by high-skilled foreign workers in the United States, but has mostly advocated for the Fairness for High Skilled Immigrants Act that benefits ...

, an activist organization *Industrievereinigung, Federation of Austrian Industry * Intellectual Ventures, a privately held intellectual property company *

InterVarsity Christian Fellowship InterVarsity Christian Fellowship/USA is an inter-denominational, evangelical Christian campus ministry founded in 1941, working with students and faculty on U.S. college and university campuses. InterVarsity is a charter member of the Interna ...

Irish Volunteers The Irish Volunteers ( ga, Óglaigh na hÉireann), sometimes called the Irish Volunteer Force or Irish Volunteer Army, was a military organisation established in 1913 by Irish nationalists and republicans. It was ostensibly formed in respon ...

, a military organization *

Italia Viva Italia Viva (, IV) is a liberal political party in Italy founded in September 2019. The party is led by Matteo Renzi, a former Prime Minister of Italy and former secretary of the Democratic Party (PD). History Background Matteo Renzi start ...

, an Italian centrist political party, led by former prime minister Matteo Renzi

Music

* Subdominant, in music theory

Recordings

* ''IV'' (The 1975 EP), 2013 * ''IV'' (The Aggrolites album), 2009 * ''IV'' (Angband album), 2020 * ''IV'' (BadBadNotGood album), 2016 * ''IV'' (Black Mountain album), 2016 * ''IV'' (Cypress Hill album), 1998 * ''IV'' (Diamond Rio album), 1996 * ''IV'' (Goatsnake album), 1998 * ''IV'' (Godsmack album), 2006 * ''IV'' (Hiroyuki Sawano album), 2021 * ''I.V.'' (Loma Prieta album), 2012 * ''IV'' (The Lookouts album), 1990 * ''IV'' (Maylene and the Sons of Disaster album), 2011 * ''IV'' (Ton Steine Scherben album), 1981 * ''IV'' (The Stranglers album), 1980 * ''IV'' (To/Die/For album), 2004 * ''IV'' (Veruca Salt album), 2006 * ''IV'' (Winger album), 2006 * "I.V." (X Japan song), an X Japan song, 2008 * ''IV'' (Željko Joksimović album), 2005 *''

Faust IV ''Faust IV'' is the fourth studio album by the German krautrock group Faust, released in 1973. The album is included in the book '' 1001 Albums You Must Hear Before You Die'', where it is referred to as a "krautrock classic". This was the las ...

'', 1973 *'' Good Apollo, I'm Burning Star IV, Volume One: From Fear Through the Eyes of Madness'', by Coheed and Cambria, 2005 *''

Led Zeppelin IV The untitled fourth studio album by the English rock band Led Zeppelin, commonly known as ''Led Zeppelin IV'', was released on 8 November 1971 by Atlantic Records. It was produced by guitarist Jimmy Page and recorded between December 1970 and ...

'', 1971 *''

Toto IV ''Toto IV'' is the fourth studio album by American rock band Toto released in the spring of 1982 by Columbia Records. The lead single, " Rosanna", peaked at number 2 for five weeks on the ''Billboard'' Hot 100 charts, while the album's third si ...

'', 1982

Places

Ivory Coast Ivory Coast, also known as Côte d'Ivoire, officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital is Yamoussoukro, in the centre of the country, while its largest city and economic centre is ...

, a country *

IV postcode area The IV postcode area, also known as the Inverness postcode area, is a group of 52 postcode districts for post towns: Achnasheen, Alness, Avoch, Beauly, Bonar Bridge, Cromarty, Dingwall, Dornoch, Elgin, Fochabers, Forres, Fortrose, Gairloch, Gar ...

, the Inverness postcode area in the UK * Isla Vista, an unincorporated community in the United States near Santa Barbara, California

In science and technology

Intravenous therapy Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutri ...

, a route of administration of a drug * I–V curve, current–voltage curve characteristic *

Implied volatility In financial mathematics, the implied volatility (IV) of an option contract is that value of the volatility of the underlying instrument which, when input in an option pricing model (such as Black–Scholes), will return a theoretical value equ ...

, a term in financial mathematics *

Independent variable Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or deman ...

, in mathematical and statistical modeling *

Independent verification systems Independent verification (IV) systems or Independent Dual Verification (IDV) are voting machines that produce at least two independent auditable records of votes where the second record is used to check the first. To be considered "independent" at ...

, in voting machines *

Initialization vector In cryptography, an initialization vector (IV) or starting variable (SV) is an input to a cryptographic primitive being used to provide the initial state. The IV is typically required to be random or pseudorandom, but sometimes an IV only needs to ...

, in cryptography *

Instrumental variable In statistics, econometrics, epidemiology and related disciplines, the method of instrumental variables (IV) is used to estimate causal relationships when controlled experiments are not feasible or when a treatment is not successfully delivered ...

, in statistics * Intrinsic value (finance), of an option or stock *

Intrinsic viscosity Intrinsic viscosity \left \eta \right/math> is a measure of a solute's contribution to the viscosity \eta of a solution. It should not be confused with inherent viscosity, which is the ratio of the natural logarithm of the relative viscosity to the ...

* Trochlear nerve, the fourth cranial nerve

Other uses

4 (number) 4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures. In mathematics Four is the smallest co ...