The term "i q" is often known to us as a measure of intelligence. However, there are synonyms and related words that can be used instead of "i q". Some terms that could be used instead of "i q" are cognitive ability, mental agility, reasoning capacity, intellectual capacity, etc. These words could be used interchangeably with "i q" especially in academic contexts. It is also important to note that while these terms might be used similarly, there could be subtle differences in their meanings, thus it may be necessary to choose the most appropriate term depending on the context in which it is being used.