Source : Webster's Revised Unabridged Dictionary (1913)

Rouleau \Rou`leau"\, n.; pl. F. {Rouleaux} (F. ?; E. ?), E.
   {Rouleaus}. [F., a roll, dim. fr. fr. r[^o]le, formerly also
   spelt roulle. See {Roll}.]
   A little roll; a roll of coins put up in paper, or something
   resembling such a roll.