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: Organisms that live in marine biomes must be adapted to the salt in the water. 
Sentence2: Most of the water on the planet is salt water in the oceans.
Example Output: salt

Example Input: Sentence1: If there is enough moisture in the clouds, rain is produced. 
Sentence2: Clouds lacking water reduces rainfall.
Example Output: clouds

Example Input: Sentence1: Visible and invisible light is energy in the form of electromagnetic waves. 
Sentence2: Eyes are used for seeing animals by sensing electromagnetic waves.
Example Output:
electromagnetic