Source : Webster's Revised Unabridged Dictionary (1913)

Loco \Lo"co\, v. t. [imp. & p. p. {Locoed}; p. pr. & vb. n.
   {Locoing}.]
   To poison with loco; to affect with the loco disease; hence
   (Colloq.), to render insane or mad. ``The locoed novelist.''
   --W. D. Howells.