Given the task definition and input, reply with output. 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.

Sentence1: Lions hunt in prides, the killing is usually done by the swifter young lions. 
Sentence2: lions are social groups that hunt.

Lions