- necessary [nes′ə ser΄ē]adj.[ME < L necessarius < necesse, unavoidable, necessary < ne-, not + cedere, to give way: see CEDE]1. that cannot be dispensed with; essential; indispensable [the nutriments necessary to life]2. resulting from necessity; inevitable [a necessary result]3.a) that must be done; mandatory; not voluntaryb) not free to choose; compelled by circumstances [a necessary agent]4. inherent in the situation; undeniable; unavoidable from the premises5. Archaic rendering some essential and intimate servicen.pl. necessaries1. a necessary thing; thing essential to life, some purpose, etc.often used in pl.2. Dial. a privy or toilet3. [pl.] Law those things essential to maintaining a dependent or incompetent in comfort and well-beingSYN.- ESSENTIAL
English World dictionary. V. Neufeldt. 2014.