The phrase "almost entirely in terms of" is correct and usable in written English.
It can be used when discussing a subject or concept that is primarily defined or understood through specific criteria or parameters.
Example: "The project's success can be evaluated almost entirely in terms of its impact on community engagement."
Alternatives: "largely based on" or "primarily regarding".
The countless references to "Mommie" in the Presidential diaries are expressed almost entirely in terms of personal need.
The party's lack of progress in the polls is now explained almost entirely in terms of Mr Duncan Smith's leadership.
Elise, the most interesting girl of the bunch, is drawn almost entirely in terms of how she reacts to a former boyfriend.
In another passage in the speech he insisted that the Conservatives were the real one-nation party, although he defined one-nation almost entirely in terms of the group also being defined as "strivers".
This character of God is conceived almost entirely in terms of ethical laws, and the rewards for their observance are defined in terms of human values; e.g., health, long life, respect, possessions, security, and self-control.
While everyday players think of life on the road almost entirely in terms of airports, hotels and stadiums, many pitchers can recite a list of the best golf courses in every big-league city.
Discussion of the skeptics' attitudes is almost entirely conducted in terms of skeptical language and the skeptical formulae (for detailed discussion of the relevant paragraphs, DL 9.74 7, cf. Corti 2015).
Their analysis of the work almost entirely in biographical terms has, at times, a doggedness, a lack of appreciation of style and form.
The chaste romance of Anne and Peter plays out almost entirely in these terms, accented by the disapproving clucks of Peter's bickering parents (Shelley Winters, who won the film's only acting Oscar, and Lou Jacobi).
Author of teenage fiction Patrick Ness in his recent Carnegie address suggested that "the worst thing our present government and, in fact, we as a culture do about teenagers is that we think of them almost entirely in negative terms".
The government defines progress almost entirely in economic terms.
