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: Spikes are forceful the tidal waves of electric current. 
Sentence2: spikes come from tidal energy.
Example Output: Spikes

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

Example Input: Sentence1: Bacteria can cause infection. 
Sentence2: Any surface that has not been sterilized could result in infection.
Example Output:
infection