"foremost need" is correct and can be used in written English.
It means the need that is most pressing or urgent. For example, at this moment, the world's foremost need is to contain the spread of the coronavirus.
Drivers, first and foremost, need to obey the rules, especially as the number of cyclists grows.
The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world.
The search for newer anti-diabetic agents is the foremost need to control the accelerating diabetic population.
"I think venture capitalists, first and foremost, need to feel like their job is to make entrepreneurs successful.
This may assist in identification of patients that are in foremost need of treatment and may respond optimally, with the highest efficacy and lowest safety concerns, to a given treatment.
"By asking, especially when taking on office: What is the foremost need of the institution and therefore my first task and duty?" In short, ask not what the institution can do for you.
One of America's foremost needs is to address inequality and cycles of poverty.
Specifically, the conventional disciplines in Rocket Science lacks foresight into the physics of acceleration to include the nature of gravity and inertia, which is foremost needed for the progression of spaceflight.
Superbly led by campaign co-chairs Bob Murley '72 and Nancy Peretsman '76, this collective effort not only addressed our University's foremost needs, it also enlarged the metaphorical tent in which Princetonians gather.
For justice to reign amid a new world order, they insisted, the working poor — women, first and foremost — needed to be able to balance wage labor and family life.
The founders, first and foremost, needs to develop that core narrative, the go-to-market message.
