The phrase "in fundamental terms" is correct and usable in written English.
You can use it when you want to explain something in a simple way, emphasizing the core or basics of the matter. For example: "In fundamental terms, the meaning of the passage is that everyone is capable of achieving their dreams."
In fundamental terms, then, the stock market's oil obsession is hard to justify.
The basis for certain empirical relationships is explained in fundamental terms.
But Justice Kennedy observed that "the amendment is cast in fundamental terms, terms transcending the particular controversy which was the immediate impetus for its enactment".
The basic principles that govern the calculations required to select pumps, valves and design installations are thus understood in fundamental terms.
In fundamental terms, however, this assumed regulation refers only to the intricate propagation of changes in gene expression or else leads to non-explanatory regresses.
It does not specifically address the many aerodynamic problems associated with such vehicles, but rather attempts to describe, in fundamental terms, the nature of the flow field.
In most fundamental terms, his theory of species change was tied to his reversal of the taxonomic ordering of forms originally presented in his early systematic arrangements.
The issue is how we are to understand the notion of an object, and whether, in the light of the correct understanding, it remains a basic notion, or one that must be characterized in more fundamental terms.
In 1954, he presented Brown v. Board of Education to his colleagues in the most fundamental terms: either they believed in the inherent inferiority of blacks or they did not, for segregation could be upheld only if they did.
Brexit demands to be debated in the most fundamental terms – but England being England, it is too often reduced to the political equivalent of small talk.
