Etymology: In senses 1, 2, and 3 partly < post-classical Latin quarentena Lent (9th cent.), place where Jesus fasted for forty days (11th cent.), period of forty days (from 12th cent. in British sources (1419 as quarentina ); 13th cent. in a continental source), period of forty days during which a widow who is entitled to a dower is supposed to be assigned her dower, and has the right to remain in her deceased husband's chief dwelling (frequently from 13th cent. in British sources; see below), and partly < Anglo-Norman quarenteine, quarenteinne (Middle French, French quarantaine ) period of forty days, especially such a period set aside for fasting or penance, (specifically) Lent (all end of the 12th cent. in Old French), place where Jesus fasted for forty days (late 14th cent.), isolation imposed on people to prevent the spread of contagious diseases (1635; in this sense perhaps after Italian), in Anglo-Norman also period of forty days' residence allowed to a widow (end of the 13th cent. or earlier; see below), with suffix substitution (see -ine suffix⁴) in the α. forms. In sense 4 probably < Italian quarantina, †quarentina (1630 in this sense, originally in the regional (Venice) form quarentena; a1311 denoting a set of forty (with reference to units of time), 14th cent. denoting a period of forty days, originally specifically one set aside for penance; see below). Post-classical Latin quarentena is apparently < an unattested post-classical Latin form *quaranta (compare post-classical Latin quarranta , 5th cent.; < classical Latin quadrāgintā forty: see Quadragesima n.) + -ēna , neuter of -ēnī , suffix forming distributive adjectives (see nonagenarian n.). Anglo-Norman quarenteine, quarenteinne and Middle French, French quarantaine are < quarante forty (first half of the 12th cent.; < post-classical Latin *quaranta ) + French -aine , suffix forming collective numerals (see quatorzain n.). Italian quarantina, †quarentina is < quaranta forty (see Quarant' Ore n.) + -ina , suffix forming collective numerals (see -ine suffix⁴).The form with -ine may have been reinforced in early use by rhyme (with pyne and wyne respectively in the earliest quots., c1470 and c1500 at sense 1). Compare Old Occitan carentena Lent (a1168), military service lasting forty days (a1219), Catalan quarentena period of forty days, originally specifically Lent (c1200 in la Santa Quarentena), isolation imposed on newly arrived travellers in order to prevent the spread of disease, a period of time spent in such isolation (late 17th cent.), Spanish cuarentena period of forty days (c1200), isolation imposed on newly arrived travellers in order to prevent the spread of disease, a period of time spent in such isolation (second half of the 17th cent.), Portuguese quarentena (14th cent., originally in sense ‘set of forty things’).

Etymology: < quarantine n.With the form quaranteen perhaps compare -een suffix¹.