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start in

British  

verb

  1. (adverb) to undertake (something or doing something); commence or begin

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

start in Idioms  
  1. Begin, as in He started in serving, without taking any practice. [Late 1800s] Also see start out.