n. 1. a. The killing of one's brother or sister. b. One who has killed one's brother or sister. 2. The accidental killing of an ally caused by a discharge of a military weapon. [Middle English, from Old French, from Latin frātricīdium and frātricīda : frāter, frātr-, brother; see bhrāter- in the Appendix of Indo-European roots + -cīdium and -cīda, -cide.] frat′ri·cidal (-sīdl) adj. |
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