"vessel with a long neck bent downward, used in chemistry for distilling or effecting decomposition by the aid of heat," c. 1600, from French retorte, from Medieval Latin *retorta "a retort, a vessel with a bent neck," literally "a thing bent or twisted," from past-participle stem of Latin retorquere "turn back, twist back, throw back," from re- "back" (see re-) + torquere "to twist" (from PIE root *terkw- "to twist").
early 15c., receden, "to depart, go away," a sense now rare or obsolete; of things, "to move back, retreat, withdraw," from Old French receder and directly from Latin recedere "to go back, fall back; withdraw, depart, retire," from re- "back" (see re-) + cedere "to go" (from PIE root *ked- "to go, yield"). Sense of "to have a backward inclination, slope, or tendency" is by 1866. Related: Receded; receding.
1550s, "to return to a former state or place, go back," from Latin regressus "a return, retreat, a going back," noun use of past participle of regredi "to go back," from re- "back" (see re-) + gradi "to step, walk" (from PIE root *ghredh- "to walk, go").
In astronomy, "appear to move in a backward direction," by 1823. The psychological sense of "to return to an earlier stage of life" is attested from 1926. Related: Regressed; regressing.