adj. 25B6; adjective
it is essential to remove the paint : CRUCIAL, necessary, key, vital, indispensable, important, all-important, of the essence, critical, imperative, mandatory, compulsory, obligatory; urgent, pressing, paramount, pre-eminent, high-priority.
the essential simplicity of his style : BASIC, inherent, fundamental, quintessential, intrinsic, underlying, characteristic, innate, primary, elementary, elemental; central, pivotal, vital.
the essential English gentleman : IDEAL, absolute, complete, perfect, quintessential.
unimportant, optional, secondary.
25B6; noun
an essential for broadcasters : NECESSITY, prerequisite, requisite, requirement, need; condition, precondition, stipulation; sine qua non; informal must.
the essentials of the job : FUNDAMENTALS, basics, rudiments, first principles, foundations, bedrock; essence, basis, core, kernel, crux, sine qua non; informal nitty-gritty, brass tacks, nuts and bolts.