We're expanding our Most Powerful Women coverage this year to spotlight rising stars whom we think have a good chance to be on our annual list someday. I'll be interviewing three of them at an upcoming MPWomen dinner in San Francisco.

Fortune reporter Jessica Shambora, who is handling the MPWomen list research this year, asked our three panelists for their definition of power. Their responses reflected common themes around the ability to choose and to make an impact.

"Power is having the freedom to choose."

-- Christine Day, 46, CEO, lululemon athletica (LULU). Day spent 20 years at Starbucks (SBUX) before joining lululemon in January.

"Those with true power share the ability to influence, inspire and, ultimately, lead people to pursue a common goal and vision."

-- Stephanie Tilenius, 41, senior vice president and general manager, eBay North America (EBAY).

"Power is about control, and is at best temporary. It's better to be powerful -- to have an enduring belief in your abilities and your possibility for impact."

-- Sukhinder Singh Cassidy, 38, president, Asia-Pacific & Latin America Operation, Google (GOOG).

We look forward to talking with them more next week!

P.S. Fortune hosted a MPWomen dinner in New York in May featuring a panel on leadership. The panelists included Ursula Burns, president of Xerox (XRX); Andrea Jung, CEO of Avon (AVP); and Ann Moore, CEO of Time Inc.

Click here to watch video of the leaders reflecting on their experiences traveling and working abroad.

Click here to watch video of the leaders discussing what it took to get to the corner office and stay there.

Click here to watch video of the leaders sharing stories about their mentors.