1. 蛇 (se): This is the most common and general term for "snake" in Cantonese. It is often used when referring to cobras, especially in everyday conversations or when the specific species is not important.
2. 眼鏡蛇 (ngaan gin se): This literally translates to "glasses snake" and specifically refers to cobras. It is used when emphasizing the characteristic features of a cobra, such as its hood, which resembles glasses.
So, depending on the context, you can use either "蛇 (se)" or "眼鏡蛇 (ngaan gin se)" to spell cobra in Cantonese.