honour killing

noun
  1. a murder committed by a male on a female relative considered to have brought dishonour to the family, usually through sexual activity forbidden by religion or tradition
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