From Longman Dictionary of Contemporary Englishturn in phrasal verb1 turn something ↔ inGIVE to give something to a person in authority, especially an illegal weapon or something lost or stolen The rebels were told to turn in their weapons and ammunition.turn something ↔ in to My wallet was turned in to the police two days later.2 turn something ↔ in American English to give back something you have borrowed or rented SYN return When do the library books have to be turned in?3 turn in something to produce a particular profit, result etc Bimec turned in net profits of £2.4 million. Last night the team turned in another dazzling performance.4 turn somebody ↔ inSC to tell the police who or where a criminal is Margrove’s wife finally turned him in.5 SLEEPto go to bed I think I’ll turn in early tonight.6 turn something ↔ in American EnglishGIVE to give a piece of work you have done to a teacher, your employer etc SYN hand in British English Have 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 escape freezing to death.• Substantial rewards were on offer to turn the rioters in to authorities.• I turned myself in to dry out, and I stayed dry.• This business involved turning my grandfather in to the authorities: for paying him less than the minimum wage. 