"fundamental root" is correct and usable in written English.
It is used to describe something that is very significant or essential and serves as a basis for more complex concepts. For example, "The fundamental root of our success lies in our team's commitment to excellence."
They outline fundamental root and branch reform.
This is the fundamental root cause of underfunding in the NHS.
"You need some kind of fundamental root to start from," she said.
Killing badgers is also morally bankrupt because it's diverting much-needed funds and energy away from tackling the fundamental root causes of the TB problem.
For all Albarn has achieved without Blur, watching him lead his three old friends in front of the sort of huge, unified crowd only this band can give him – one reason pop exists – they still look like the fundamental root of his music.
"The fundamental root cause is that at the time of confirmation of the project [in 2008], the budget that NASA was presented with was basically flawed," he said.
And then as they sing all that from the mountain top, in October there comes an answering contralto – Jeremy Hunt, the Tories' shadow culture secretary, says: "[We will have] a very fundamental root-and-branch discussion with the BBC about all its activities across the piece".
The brilliant, fundamental roots of the Diablo game-play style are both psychological and neuromuscular.
But Labour's simultaneous espousal of neo-liberal economic and social policy denied them the means to tackle the fundamental roots of crime.
But the fundamental roots of my belief, evolutionary psychology, that human beings are the way they are primarily because of nature rather than nurture, is fixed.
Dispersed more widely across the novel is a suggestion that, while proliferating stories might be good for dealing with hybridity, there is a countervailing need for fundamental roots.
