| a. | 1. | Such as must be; impossible to be otherwise; not to be avoided; inevitable. |
| 2. | Impossible to be otherwise, or to be dispensed with, without preventing the attainment of a desired result; indispensable; requisite; essential. | |
| 3. | Acting from necessity or compulsion; involuntary; - opposed to | |
| n. | 1. | A thing that is necessary or indispensable to some purpose; something that one can not do without; a requisite; an essential; - used chiefly in the plural; |
| 2. | A privy; a water-closet. | |
| 3. | (Law) Such things, in respect to infants, lunatics, and married women, as are requisite for support suitable to station. |
| Noun | 1. | necessary - anything indispensable; "food and shelter are necessities of life"; "the essentials of the good life"; "allow farmers to buy their requirements under favorable conditions"; "a place where the requisites of water fuel and fodder can be obtained" |
| Adj. | 1. | necessary - absolutely essential Antonyms: unnecessary, unneeded - not necessary |
| 2. | necessary - unavoidably determined by prior circumstances; "the necessary consequences of one's actions" |