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: Landslides Seismic vibration is a common triggering mechanism for landslides. 
Sentence2: Erosion can cause seismic vibrations which are triggering mechanisms.
Example Output: Seismic

Example Input: Sentence1: creating wood-free paper does not require cutting down trees. 
Sentence2: creating printed media requires cutting down trees.
Example Output: creating

Example Input: Sentence1: Speed is in miles per hour and distance is in miles with yards as a sub-measure. 
Sentence2: Speedometers are used to give a driver feedback on how many miles per hour their vehicle goes.
Example Output:
hour