These words come into comparison as verbal equivalents of the symbol for nothing, 0. The choice of which one to use depends upon a context that may range from the archaic and informal to the mathematical and scientific.

Zero and cipher both come from the Arabic word sifr , meaning empty. In this sense zero has come to be the most commonly used to indicate the absence or negation of something.

• Subtracting any number from itself gives zero ; The results of all the tests were zero .

It is also regarded as the standard reference point in any scale of values, quantities, magnitudes, dimensions, etc.

• The temperature was 10 below (or above) zero ; The gambler bet on zero at roulette; Heavy fog reduced visibility to zero .

Cipher , though literally synonymous, cannot replace zero in any of the above examples. It is still thought of as representing any numeral from 0 to 9, a use carried over from the verb form meaning to count or calculate. We can, of course, increase the value of any whole number by adding ciphers at the end of it, but the distinction is recognized by saying that the enlarged number, say 643,000, contains three zeros , not ciphers . Nevertheless, the idea of nullity or nonentity is usually clear from the context, especially if we are using the word in a figurative sense: man is a mere cipher in the universe.

Naught (sometimes spelt nought ), an Old English word for nothing, doubles for cipher in its literal sense,

• This number has a lot of noughts in it; Let’s play noughts and crosses.

But this use is mostly colloquial, though less so than the clipped version aught (a naught taken as an aught ). As an epithet for a person or thing devoid of merit or value, naught still has poetic force.

• All his plans came to naught ; There was naught to be done in the emergency but wait.

Nil is very common for nothing, especially in relation to scoring: we won three sets to nil . It still has considerable general application: All our efforts were nil against his greater experience. Null is best known to us in the duplicated legal phrase "null and void ," meaning without force or effect, or invalid. But it also serves a useful purpose to indicate a negative result or outcome, especially in certain types of scientific work.

• All the Geiger counter readings were null ; The results of the first experiments to prove the value of the new drug were null .