The phrase "a large and formidable" is correct and usable in written English.
It can be used to describe something that is both big in size and impressive or intimidating in nature.
Example: "The castle stood on the hill, a large and formidable structure that had withstood centuries of storms."
Alternatives: "a big and imposing" or "a massive and intimidating".
Having derived great wealth from its crown lands, the dynasty gained control of Serbia and Galicia and made Hungary a large and formidable power in east-central Europe.
Piyamaradus used Millawanda (possibly Miletus) as his base; that city was a dependency of Ahhiyawa, a large and formidable country, the identity and geographic location of which have been the subject of prolonged controversy.
In 1513 these systems were successful in producing a large and formidable force, but there is evidence that by the mid-sixteenth century the authorities were experiencing increasing difficulty in recruitment.
Esau vows to kill Jacob, and even after establishing a large family and formidable wealth and power, Jacob still fears his brother as he waits for a fateful reunion alone by the banks of a stream.
The successful Parliamentarians were able, after their victory, to attack and successfully besiege Arundel, a larger and more formidable Royalist outpost in the south of England.
When the life was that of a formidable politician with a large and passionate following, such speculation becomes an important civic act, clarifying the nation's trajectory and the possibilities that may have been closed by the person's death.
Nasaw's biography — one of the Book Review's 10 Best Books of 2012 — captures the sweep of Kennedy's life and persuasively makes the case that he was the most fascinating member of his large, famous and formidable family.
Furthermore, GSE bonds are held in huge numbers by large companies and formidable countries.
Because of its large size and formidable defenses, The Pacific electric ray seldom falls prey to other animals.
Loving husband, of Shahara and father of four daughters he was a figure larger than life and formidable in his interests.
"China is a formidable country with a large economy and a modern military," he explains.
