to be reckoned with

(someone or something) to be reckoned with

A person or thing considered to be especially strong, influential, or difficult to defeat. Most commonly used in the phrase "a force to be reckoned with." Despite the higher age of its star players, they are still a team to be reckoned with. The attorney may look petite and meek, but she's a force to be reckoned with in the courtroom.
See also: reckon
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

a — to be reckoned with (or to reckon with)

a thing or person of considerable importance or ability that is not to be ignored or underestimated.
2002 New Internationalist Now nearly 80, the ex-Harvard Pro is still full of brio and a force to be reckoned with.
See also: reckon
Farlex Partner Idioms Dictionary © Farlex 2017
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References in periodicals archive ?
WES YORK is confident Wrexham will be a force to be reckoned with when everything finally gels.
Liverpool have got Real Madrid but the Spanish are no longer a force to be reckoned with despite winning the competition a record nine times.
We have to quit feeling sorry for ourselves, pointing blame in every direction, and prove to the world that we're still a force to be reckoned with. Sure, we can debate the problems facing the industry to death, but sitting around gabbing isn't going to do us any good.
Tommy is already a force to be reckoned with, so I can only imagine what the future holds.
Affluent, and often socially liberal, baby boomers have embraced the four-wheel-drive SUV as a symbol of their ability to defy the conventions of old age, of their independence and "outdoorsiness," making the off-road vehicle a force to be reckoned with on the American blacktop.
Holmes, 30, is now injury-free and thriving after three weeks of warm weather training in South Africa and admitted: 'I am looking to make my mark early this year and let the rest of the world know I am still a force to be reckoned with.'