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: Capillaries are microscopic vessels. 
Sentence2: Lymph is a fluid that leaks out of microscopic vessels into spaces between cells.
Example Output: microscopic

Example Input: Sentence1: Some mollusks are nearly microscopic. 
Sentence2: Some squids are nearly microscopic.
Example Output: Some

Example Input: Sentence1: Orchids often have fleshy pods and waxy leaves which can store water. 
Sentence2: Orchids keep water in their leaves.
Example Output:
Orchids