[pis-tl-air-oh; Spanish pees-taw-le-raw]
noun, plural pis·to·le·ros [pis-tl-air-ohz; Spanish pees-taw-le-raws] /ˌpɪs tlˈɛər oʊz; Spanish ˌpis tɔˈlɛ rɔs/. (esp. in Mexico and Central America)
  1. a member of an armed band of roving mounted bandits.
  2. a gunman or hired killer.

Origin of pistolero

1935–40; < Spanish, equivalent to pistol(a) pistol + -ero < Latin -ārius -ary
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Word Origin and History for pistolero

1937, from Spanish; see pistolier.

Online Etymology Dictionary, © 2010 Douglas Harper