List of 426 Sets of Synonyms - How they Differ - Total of 2307 Words - 254

SYNONYMS: necessary, essential, vital, indispensable, requisite, required, perquisite, necessitous, needy, needful.
These adjectives refer to things and their status of fulfillment.

Necessary denotes that which fills an urgent need, but not invariably an all-compelling need.
The stronger essential and vital are applied to that without which something, by its nature, cannot exist, or continue in a normal condition or form.
Indispensable even more specifically denotes that which cannot be sacrificed; frequently it is applied to part of a whole.
Requisite and required are more specific and less powerful terms; they usually signify a need that complements other needs and is imposed externally rather than by the nature of the subject itself.
Perquisite adds the dimension of need that must be met beforehand; it specifies a prior condition that determines whether something desired is to follow.
Necessitous and needy signify want in the subjective sense of privation, and are applied to persons in a condition of great want.
Needful expresses want much more urgently than any of the foregoing.