For cedilla being the diminutive of ceda, see definition of cedilla, Diccionario de la lengua española, 22nd edition, Real Academia Española (in Spanish), which can be seen in context by accessing the site of the Real Academia and searching for cedilla.
Ç Ş definition of cedilla, Diccionario de la lengua española, 22nd edition, الأكاديمية الملكية الإسبانية (بالإسبانية), which can be seen in context by accessing the site of the Real Academia and searching for cedilla.