a. the act of killing one's own brother or sister
b. the act of killing relatives or fellow-countrymen, as in a civil war
2. a person who kills his or her own brother or sister
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'fratricide'
Fr < LL(Ec) fratricidium
< L fratricida
, one who kills a brother < frater
, to kill (see -cide
); (sense 2) ME < OFr < L fratricida