Source : Webster's Revised Unabridged Dictionary (1913)

Nonessential \Non`es*sen"tial\, n.
   A thing not essential.

Nonessential \Non`es*sen"tial\, a.
   Not essential.

Source : WordNet®

nonessential
     adj : not of prime or central importance; "nonessential to the
           integral meanings of poetry"- Pubs.MLA [syn: {incidental}]
     n : anything that is not essential; "they discarded all their
         inessentials" [syn: {inessential}] [ant: {necessity}]