Exile is a type of punishment in which a person must leave their home and is forbidden to return.
After their attempt to take over the Celestial Temple, the Pah-wraith were exiled to the Fire Caves. (DS9: "The Assignment")
The Romulan composer Frenchotte's exile was self-imposed. (DS9: "Playing God")
Among the Trill species, reassociation is punished by exile. (DS9: "Rejoined")
Exile was a popular method of punishment used by the Cardassians. Famous people to be exiled from Cardassia include Iloja of Prim and Tavor Kell. Iloja settle on Vulcan where Tobin Dax met him. (DS9: "Destiny", "The Muse")
Major Kira Nerys hoped that Tekeny Ghemor would set up an exile Cardassian government on Deep Space 9 to oppose the newly Dominion controlled Cardassian Union. The plan was abandoned, as Ghemor was terminally ill with Yarim Fel Syndrome. (DS9: "Ties of Blood and Water")
Elim Garak was exiled as well, although the reasons are unknown. Several reasons he told for his exile included destroying a Cardassian shuttle, that he had showed mercy and let several Bajoran children escape interrogation, that he had been betrayed by "Elim" and that he had not paid his taxes. (DS9: "The Wire", "Improbable Cause") The reasons for Garak's exile may be unknown, but Enabran Tain was involved. (DS9: "In Purgatory's Shadow")
Garak had a chance to end his exile in 2370, by apprehending Natima Lang, Hogue and Rekelen on Deep Space 9, but chose not to, after finding out that Gul Toran had tricked him. (DS9: "Profit and Loss") Garak's exile finally ended in 2375. (DS9: "What You Leave Behind")
Exile was one of the consequences that Brunt told Quark (in a vision) for a Ferengi who broke a contract. (DS9: "Body Parts")
The Doctor commented that the great defender Torelius would go into voluntary exile if he were alive to see his sports team, the Mountain, performing so poorly in the current season. (VOY: "Blink of an Eye")
Tom Paris once rebutted to Harry Kim that fatherhood was not the same thing as being exiled. (VOY: "Lineage")
In the late 23rd century, the Ba'ku exiled a group of their children, which eventually became the Son'a. (Star Trek: Insurrection)