As the question states: 1 is primary, 2 is secondary, and so on.

Given this pattern, what is 0? I've heard zeronary and nullary but I have no idea which is correct (if either). I've heard zeronary used in software documentation to refer to a set of data points equal to zero but never in actual conversation, and I'm struggling to think of when you'd even be able to use it.

  • 6
    In lists that begin with index 0, 0 would be primary. ^_^
    – Robusto
    Sep 2, 2015 at 16:27
  • 5
    'nullary' is for where the number of arguments is zeo, analogous to unary, binary, ternary. Primary and secondary are for importance. Since there's nothing more important than first, there is no 'zeroth' corresponding ordinal. If forced, I wouldn't say 'zeronary' (I've never heard that one and it sounds awful), I'd go with 'zero-ary' (because 'n-ary' is the generalization)
    – Mitch
    Sep 2, 2015 at 16:27
  • 8
    ... preliminary
    – jxh
    Sep 2, 2015 at 17:52
  • For US educational levels/sequence: kindergarten, or pre-school (similar to @jxh). Sep 3, 2015 at 1:02
  • 2
    The question needs to explain what sense of "primary, secondary..." it's referring to, and what the sought word would actually mean. If there's no logical meaning for it, then there shouldn't be such a word.
    – Ypnypn
    Sep 3, 2015 at 4:01

4 Answers 4


Historically no such word exists. Primary, secondary, etc. come from Latin and ancient Rome. The Romans however, had no concept of 0. The closest they knew was 'none' (English translation). There is an old joke about this very question, to which the answer is "nunnery"/"noneary" :)

In recent years the term 'nullary' has won popularity in certain technical areas, mainly mathematics and computer science. Although the word exists, generally it doesn't make sense outside the particular field, because "There can be none before the first" (meaning: primary/secondary/etc. are labels you apply in order, if nullary were a word, it would label a thing that isn't there. But a thing that isn't there cannot be labeled.)

  • That which comes before Primary we call a Temporary, but it's probably not what you want.
    – Joshua
    Sep 2, 2015 at 22:56

If you think of Primary, Secondary, etc.,as events, then zero precedes all events, but is not itself an event. It is a lack of events. It defines the state of the system prior to any events, so it is not comparable.

  • 1
    Then wouldn't that make 0 "initial conditions"? Sep 3, 2015 at 4:02

"O" would be the entirety of the entity composed of primary, secondary, tertiary and so on multiple aspects.

  • The primary function is the principal and main function. The secondary one is usable in case the first one malfunctions. No relation in fact exist unless adjunct to a matrix.
    – user230919
    Jun 8, 2017 at 23:44
  • or the lack / lackery...
    – user230919
    Jun 8, 2017 at 23:48

Nullary is what is used. From the Wikipedia article on Arity:

Sometimes it is useful to consider a constant to be an operation of arity 0, and hence call it nullary.

  • 8
    "Nullary" is the counterpart to "unary"/"binary"/"ternary", not "primary"/"secondary"/"tertiary". Sep 2, 2015 at 22:34

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