From Longman Dictionary of Contemporary Englishturn in phrasal verb1turn something ↔ inGIVE to give something to a person in authority, especially an illegalweapon or something lost or stolenThe rebels were told to turn in their weapons and ammunition.turn something ↔ in toMy wallet was turned in to the police two days later.2turn something ↔ in American English to give back something you have borrowed or rented syn returnWhen do the library books have to be turned in?3turn in something to produce a particular profit, result etcBimec turned in net profits of £2.4 million.Last night the team turned in another dazzling performance.4turn somebody ↔ inSC to tell the police who or where a criminal isMargrove’s wife finally turned him in.5SLEEPto go to bedI think I’ll turn in early tonight.6turn something ↔ in American EnglishGIVE to give a piece of work you have done to a teacher, your employer etc syn hand in British EnglishHave you all turned in your homework assignments? →turn→ See Verb table
Examples from the Corpus
turn in• Come on you guys, it's time to turn in.• I'm going to have to turn in. I'm not used to these late nights.turn to• Dozens of immigrants have turned themselves in to authorities to escapefreezing to death.• Substantialrewards were on offer to turn the rioters in to authorities.• I turned myself in todry out, and I stayed dry.• This business involvedturning my grandfather in to the authorities: for paying him less than the minimumwage.