The phrase "a formidable means" is correct and usable in written English.
It can be used to describe a powerful or effective method or way of achieving something.
Example: "The new technology provides a formidable means of improving efficiency in the manufacturing process."
Alternatives: "an effective method" or "a powerful approach."
Yasir Arafat may not be able to prevent every Palestinian terrorist from attacking Israelis, but he has formidable means of political persuasion and police compulsion at his disposal.
This means a formidable coalition of forces controlling a process that steadily and peacefully steers Syria away from its Ba'athist domination and violence.
Global emergence of pathogenic infectious diseases by both natural and intentional means presents a formidable challenge to infectious disease surveillance and response, namely timely and efficient pathogen detection.
As accounting for the former is quite a formidable problem, we estimate the mean value < L > at different moments in the course of the substorm.
He had not meant to marry a formidable and feted writer, but that was how things turned out, after he saw her, one day in 1954, cycling laboriously past his college window.
Even among the 15 current members, there are differences in industrial and economic activity, language and culture that make closer cooperation -- of the kind that the constitution is meant to promote -- a formidable challenge.
But I still believe Biden was honestly trying to size up a rival and admit that Obama was a formidable candidate -- in other words, he meant everything he said in a positive way.
Many of the Athenians figured that meant they should seek protection behind a formidable wooden barricade.
None of this means that the NRA is not still a formidable foe.
"He's a formidable candidate".
That was a formidable problem.
