Adjective

(en adjective)

causing fear, dread, awe or admiration as a result of size, strength, or some other impressive quality; commanding respect; causing wonder or astonishment

difficult to defeat or overcome

* {{quote-news

, year=2012 , date=May 9 , author=John Percy , title=Birmingham City 2 Blackpool 2 (2-3 on agg): match report , work=the Telegraph citation , page= , passage=Holloway has unfinished business in the Premier League after relegation last year and he will make a swift return if he can overcome West Ham a week on Saturday. Sam Allardyce, the West Ham manager, will be acutely aware that when the stakes are high, Blackpool are simply formidable .}}

Adjective

(en-adj)

Having, or capable of exerting power, potency or influence.

* (William Shakespeare)

The powerful grace that lies / In herbs, plants, stones, and their true qualities.

*{{quote-book, year=1963, author=(Margery Allingham), title=(The China Governess)

, chapter=19 citation , passage=As soon as Julia returned with a constable, Timothy, who was on the point of exhaustion, prepared to give over to him gratefully. The newcomer turned out to be a powerful youngster, fully trained and eager to help, and he stripped off his tunic at once.}}

(mining) Large; capacious; said of veins of ore.