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: Combustion-related, motor vehicles, wood burning, open burning, industrial processes. 
Sentence2: Combustion is used to produce heat.
Example Output: Combustion-related

Example Input: Sentence1: infection can cause bodily tissues to swell. 
Sentence2: Bacteria can cause bodily tissues to swell.
Example Output: bodily

Example Input: Sentence1: Climate, on the other hand, looks at long-term averages of weather conditions. 
Sentence2: Climate looks at long-term averages in an area over a long period of time.
Example Output:
averages