Definition: Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
Input: Sentence1: When iron oxidizes it produces iron oxide, more commonly referred to as rust. 
Sentence2: Chemical weathering of iron in rock causes rust.

rust