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.

Example Input: Sentence1: Precipitation falls on the windward side of the mountain range. 
Sentence2: Sheep tend to favour the windward side of a paddock.
Example Output: windward

Example Input: Sentence1: Centrioles come in pairs. 
Sentence2: Something that comes in pairs are organelles involved in cell division.
Example Output: come

Example Input: Sentence1: Sediment is made of rocks, dirt, and earth. 
Sentence2: Weathering breaks down rocks, dirt, and earth to create a substance.
Example Output:
dirt