N-COUNT 鼻音化符号，腭化符号(西班牙语标在字母 n上，葡萄牙语标在字母 o 和 a 上) A tilde is a symbol that is written over the letter 'n' in Spanish ñ and the letters 'o' õ and 'a' ã in Portuguese to indicate the way in which they should be pronounced. 鼻音化符号，腭化符号(西班牙语标在字母 n上，葡萄牙语标在字母 o 和 a 上)