What do you call two words that have the same spelling or pronunciation but different meanings?

The correct term for two words that have the same spelling or pronunciation but different meanings is homographs. Homographs are a specific type of homonym wherein the words can either be spelled the same or pronounced alike and may have completely different definitions, depending on the context in which they are used. For example, the word "lead" (to guide) and "lead" (a type of metal) is a classic case of a homograph.

While homophones refer specifically to words that sound the same regardless of their spelling (like "pair" and "pear"), antonyms are words with opposite meanings (like "hot" and "cold"), and synonyms are words with similar meanings (like "happy" and "joyful"), these terms do not accurately describe the relationship of spelling or pronunciation shared by homographs. Therefore, homographs aptly capture the essence of the relationship described in the question.