cedilla
Concise Oxford English Dictionary © 2008 Oxford University Press:
cedilla /sɪˈdɪlə/
▶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.
'cedilla' also found in these Oxford entries:

