verb

• Of an event, situation, etc.: to appear or happen again, especially repeatedly.
  "The bullet had grazed the optic nerve. […] The oculist had warned him that the trouble might recur, that he ought to have remained under observation. Well, it had recurred about four months ago."
• (dated) To speak, think, or write about something again; to go back or return to a memory, a subject, etc.
  "But firſt I ſhall recurre, and give a touch upon the nature of Gravity."
• (archaic) Followed by to, or (Scotland, obsolete) on or upon: to have recourse to someone or something for assistance, support, etc.; to appeal, to resort, to turn to.
  "[I]f his Grace vvere minded, or vvould intend to do a thing inique or injuſt, there vvere no need to recurr unto the Pope's Holineſe for doing thereof."
• (computing) Synonym of recurse (“to execute a procedure recursively”).