Noun

• S: (n) indispensability, indispensableness, vitalness (the quality possessed by something that you cannot possibly do without)
• direct hypernym / inherited hypernym / sister term
• S: (n) essentiality, essentialness (basic importance)
• S: (n) importance (the quality of being important and worthy of note) "the importance of a well-balanced diet"
• S: (n) value (the quality (positive or negative) that renders something desirable or valuable) "the Shakespearean Shylock is of dubious value in the modern world"
• S: (n) worth (the quality that renders something desirable or valuable or useful)
• S: (n) quality (an essential and distinguishing attribute of something or someone) "the quality of mercy is not strained"--Shakespeare
• S: (n) attribute (an abstraction belonging to or characteristic of an entity)
• S: (n) abstraction, abstract entity (a general concept formed by extracting common features from specific examples)
• S: (n) entity (that which is perceived or known or inferred to have its own distinct existence (living or nonliving))
• antonym
• derivationally related form