A viscount is a member of the European nobility, especially of France, and of the British peerage, where a viscount ranks above a baron, below an earl (a count in France), and corresponds in Britain to the Anglo-Saxon shire reeve. A viscount is said to hold a "viscounty" or "viscountcy". The female equivalent of a viscount is a viscountess.
In the pronunciation of "viscount" and French "vicomte", the 's' is silent, in English pronounced like "vie-count".
The title of viscount is less common in Italy ("visconte"), though the noble Visconti family, rulers of Milan, offer an outstanding example. There is no German title of viscount: a Baron ranks below a Graf.
In Portugal a visconde ranks above a barão (baron) and below a conde. The first Portuguese viscountcy, that of D. Leonel de Lima, visconde de Vila Nova de Cerveira, dates from the reign of Afonso V. A flood of viscountcies, some 86 new titles, was awarded in Portugal between 1848 and 1880 (Portuguese Wikipedia).
In Spain the title was awarded from from the reign of Filipe IV until 1846
In British practice, the title of a viscount may be either a placename, or a surname, or, as is more often the case, a combination thereof. In any event, the style of a viscount is "The Viscount X," or "The Viscount X of Y." Examples include: The Viscount Falmouth (placename); The Viscount Hardinge (surname); The Viscount Gage of Castle Island (surname of placename); and The Viscount Combermere of Bhurtpore (placename of placename). An exception exists for Viscounts in the peerage of Scotland, who are styled "The Viscount of X," as in: The Viscount of Arbuthnott (surname).
Normally, a British viscount is known as Lord X, while his wife is Lady X. The children of a viscount are known as The Honourable [Forename] [Surname].
In the history of the title, the word derives from the Latin vice comes an appointed deputy of a count. Thus viscounts were not originally normally given their titles by the monarch. In Italy, a younger member of the count's family, assigned a fortified rocca on the outskirts of the territory, would be more likely to be "X, dei conti Y" ("X, of the counts of Y") than a viscount.
- Burke's Peerage & Baronetage, 1956, introduction, pp cxx-cxxviii.