[ sɪ'dɪlə ]
■ noun a mark (¸) written under the letter c , especially in French, to show that it is pronounced like an s rather than a k (e.g. façade ).
↘a similar mark under s in Turkish and other languages.
Origin
C16: from obs. Sp., earlier form of zedilla , dimin. of zeda (the letter Z), from Gk zēta .