We found 4 dictionaries that define the word mass murderers:

General (4 matching dictionaries)

1. mass murderers: Collins English Dictionary
2. mass murderers: Vocabulary.com
3. mass-murderers: Wordnik
4. mass murderers: Wiktionary

(Note: See mass_murderer as well.)

Definitions from Wiktionary (mass murderer) ▸ noun:  Someone who commits a mass murder. ▸ Also see mass_murderer ▸ Words similar to mass murderers ▸ Usage examples for mass murderers ▸ Idioms related to mass murderers ▸ Wikipedia articles (New!) ▸ Words that often appear near mass murderers ▸ Rhymes of mass murderers ▸ Invented words related to mass murderers