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: An intense bright light produces a glare. 
Sentence2: Nuclear reactions in stars cause stars to produce bright glares.
Example Output: bright

Example Input: Sentence1: Pregnancy is the carrying of one or more offspring from fertilization until birth. 
Sentence2: An elephant carries their offspring from fertilization until birth, 22 months later.
Example Output: fertilization

Example Input: Sentence1: Because the daylight changes with the seasons, ActiveEarth does, too. 
Sentence2: the Earth revolving around the Sun causes daylight changes.
Example Output:
changes