Source : Webster's Revised Unabridged Dictionary (1913)

Avignon berry \A`vignon" ber"ry\ (Bot.)
   The fruit of the {Rhamnus infectorius}, eand of other species
   of the same genus; -- so called from the city of Avignon, in
   France. It is used by dyers and painters for coloring yellow.
   Called also {French berry}.