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: Microbes are also called bacteria or microorganisms. 
Sentence2: Disease-causing bacteria have a negative impact on the body.
Example Output: bacteria

Example Input: Sentence1: Earthquakes are natural disasters. 
Sentence2: earthquakes can cause animals to leave an environment.
Example Output: Earthquakes

Example Input: Sentence1: the digestive system breaks food into nutrients for the body. 
Sentence2: Meat is a nutrient-dense food.
Example Output:
food