Ayatollah is a slur used to describe Persians in a derogatory way. A religious leader amongst Shiite Muslims. More specifically, it would refer to Iranians.
The word Ayatollah is a racial slur that has been used historically to degrade and dehumanize persians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to persians. If you are unsure about whether or not it is appropriate to use the word Ayatollah, it is best to err on the side of caution and avoid using it in any situation.