Retire, of course... requires masterwork fishing pole, meager bedroom and dining room, a masterwork crossbow and bolts, and a mangy dog. Your selected dwarf stays behind, with a random selection of other retirees.
Urist Felldown the Badly Broken Hip-bone of Ancients, Age 103:
"So long boys! I's fixin ta git mah fishin pole n ketch sum carp fer dinner. Yall can send me a scribblin of yer new digs when yall gits there."
You should be able to visit them to hear about the Legends:
"Back in mah day, son, we din have no spiffy aquafairies or no special pumpin machines. Din have no Z Axis neither! We had one Z Level and we loved it! I remember when ole Throm busted through that obsidian wall, oh boy was he suprised! Got hot that night, lemme tell you.... <Blah>"