Definition for Inverse function
From Biology Forums Dictionary
1) In mathematics, an inverse function is a function that will "undo" anything that the original function does. For example, we all have a way of tying our shoes, and how we tie our shoes could be called a function. So, what would be the inverse function of tying our shoes? The inverse function would be "untying" our shoes, because "untying" your shoes will "undo" the original function of tying our shoes.
2) The explicit form of an equation that is a change of the isolated variable from dependent to independent.