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: Endospores are commonly found in soil and water. 
Sentence2: Some bacteria form resistant cells called endospores.
Example Output: Endospores

Example Input: Sentence1: soil is formed by weathering. 
Sentence2: Something described as loamy is formed by weathering.
Example Output: formed

Example Input: Sentence1: Results can be damaging or disastrous. 
Sentence2: Lack of immunization can be damaging or disastrous.
Example Output:
damaging