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: dew is formed when water vapor condenses over night. 
Sentence2: Condensing is a gas turning into a liquid.
Example Output: condenses

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

Example Input: Sentence1: Mammals took advantage of the extinction of the dinosaurs. 
Sentence2: mammals existed in the mesozoic era.
Example Output:
Mammals