ce·dil·la 
(sĭ-dĭlə)
(sĭ-dĭlə)n.
A mark ( ¸ ) placed beneath the letter c, as in the spelling of the French word garçon, to indicate that the letter is to be pronounced (s).
[Obsolete Spanish, diminutive of ceda, the letter z (so called because a small z was formerly written after a c, and later below it, to indicate that the normal hard c was to be pronounced as a sibilant, like s or z), from Late Latin zēta, zeta, from Greek; see ZETA.]