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: Weather refers to the circulation of the Earth's atmosphere. 
Sentence2: climate is the average circulation of the Earth's atmosphere over a long period of time.

atmosphere