The Collaborative International Dictionary of English v.0.48:

Fils \Fils\, n. [F., fr. L. filius. See Filial.]
   Son; -- sometimes used after a French proper name to
   distinguish a son from his father, as, Alexandre Dumas, fils.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

fils
    n 1: 100 Yemeni fils are worth one Yemeni rial [syn: Yemeni
         fils, fils]
    2: a fractional monetary unit in Bahrain and Iraq and Jordan and
       Kuwait; equal to one thousandth of a dinar