necessity

As nouns the difference between necessity and choice

is that necessity is (quality or state of being necessary, unavoidable, or absolutely requisite) The quality or state of being necessary, unavoidable, or absolutely requisite while choice is an option; a decision; an opportunity to choose or select something.

As an adjective choice is

especially good or preferred.

As nouns the difference between necessity and settle

is that necessity is the quality or state of being necessary, unavoidable, or absolutely requisite while settle is (archaic) a seat of any kind.

As a verb settle is

to place in a fixed or permanent condition; to make firm, steady, or stable; to establish; to fix; especially, to establish in life; to fix in business, in a home etc.

As a noun necessity

is the quality or state of being necessary, unavoidable, or absolutely requisite.

As a verb required is

(require).

Prerequisite is a synonym of necessity.

As nouns the difference between necessity and prerequisite

is that necessity is (quality or state of being necessary, unavoidable, or absolutely requisite) The quality or state of being necessary, unavoidable, or absolutely requisite while prerequisite is something that must be gained in order to gain something else.

As an adjective prerequisite is

required as a prior condition of something else; necessary or indispensable.

As nouns the difference between essential and necessity

is that essential is a necessary ingredient while necessity is (quality or state of being necessary, unavoidable, or absolutely requisite) The quality or state of being necessary, unavoidable, or absolutely requisite.

As an adjective essential

is necessary.

As a noun necessity

is the quality or state of being necessary, unavoidable, or absolutely requisite.

As an adverb needsly is

(obsolete) of necessity; for some pressing reason.

As nouns the difference between necessity and nonnecessity

is that necessity is the quality or state of being necessary, unavoidable, or absolutely requisite while nonnecessity is that which is not a necessity.

Unnecessariness is a antonym of necessity.

As nouns the difference between necessity and unnecessariness

is that necessity is (quality or state of being necessary, unavoidable, or absolutely requisite) The quality or state of being necessary, unavoidable, or absolutely requisite while unnecessariness is the state or characteristic of being unnecessary.