Homonyms are generally defined as words different in meaning but

Homonyms are generally defined as words different in meaning but either identical both in sound and ( ) or identical only in sound or spelling.
【正确答案】：SPELLING
【题目解析】：同形同音异义词一般被定义为意义不同的词，但在发音和拼写上都相同，或仅在声音或拼写上相同。