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: Most fungi get organic compounds from dead organisms. 
Sentence2: Moulds, yeasts, rusts, smuts, mildews, and mushrooms are all types of fungi.
Example Output: fungi

Example Input: Sentence1: Most mammals have hair, or fur, covering their body. 
Sentence2: Most mammals have a body covering for keeping warm.
Example Output: body

Example Input: Sentence1: Cells are organized into tissues, and tissues form organs. 
Sentence2: Bacteria are one-celled organisms.
Example Output:
Cells