Now universally taken as a pet form of Jennifer. In fact, this name existed during the Middle Ages as a pet form of Jean. It is often used independently. Among many well-known bearers are the Swedish soprano Jenny Lind (originally Johanna Lind, 1820–87), the British racehorse trainer Jenny Pitman (b. 1946), and the British actress Jenny Agutter (b. 1952).
Irish: Anglicized form of Gaelic Ó Macháin ‘descendant of Machán’, which Woulfe suggests is a variant of Mochán, a diminutive of moch ‘early’, itself a short form of a name formed with this element, of which there are several, and a variant of Mohan of Kilmacduagh in County Galway.