N
Abbreviation with 9 meanings
| Stands for | North |
|---|---|
| Meanings | 9 |
| Categories | Geography & Places, Units & Measurements, Science & Engineering, Writing & Everyday |
| Also written | n, n. |
N has nine meanings. The most common are North (direction) and Newton (metric and SI unit); it can also stand for Sample size, Nitrogen, Noun, Nano- (billionth) and Population size (total sample size), plus 2 more listed below.
Meanings of N at a glance
| # | N stands for | Context |
|---|---|---|
| 1 | North | Geography & Places › Direction |
| 2 | Newton | Units & Measurements › Metric and SI Unit |
| 3 | Sample size | Units & Measurements › Statistics |
| 4 | Nitrogen | Science & Engineering › Chemical Element |
| 5 | Noun | Writing & Everyday › Grammar and Dictionary |
| 6 | Nano- (billionth) | Units & Measurements › Metric and SI Unit |
| 7 | Population size (total sample size) | Units & Measurements › Statistics |
| 8 | Note | Writing & Everyday › Citation and Bibliography |
| 9 | Natural numbers | Units & Measurements › Math |
1. North
Geography & Places · Direction Abbreviations
Cardinal direction toward the North Pole, at 0 or 360 degrees on a compass, and the direction at the top of most modern maps. In US addresses N is a directional prefix, as in 400 N Michigan Ave, showing which side of a city's baseline the address lies on.
Example: The parking garage entrance is on N Clark St, just past the theater.
USPS standard directionals are N, S, E, W, NE, NW, SE and SW, written without periods. Many medieval European maps placed east at the top instead, the origin of the word orientation. In science N also means newton and nitrogen.
2. Newton
Units & Measurements · Metric and SI Unit Abbreviations
Force that accelerates a 1 kg mass at 1 meter per second squared, the SI unit for push, pull and weight. A small apple weighs roughly 1 N on Earth, and a 70 kg person about 690 N.
Example: The wall bracket is rated for a static load of 500 N.
Named in 1948 after Isaac Newton. The symbol is capitalized because it honors a person, while the unit name is written lowercase: newton. Torque specifications combine it with meters as N·m, often typed Nm. Bathroom scales display kilograms because they divide the measured force by standard gravity.
3. Sample size (n)
Units & Measurements · Statistics Abbreviations
The number of observations in a sample or subgroup, written lowercase n in research reports. Statistical power, standard errors and degrees of freedom all depend on it.
Example: Of the participants, n = 48 were assigned to the treatment group and n = 52 to the control group.
APA style uses uppercase N for the total sample and lowercase n for subgroups. Sample-size calculations before a study determine the n needed to detect an effect of a given size with adequate power, typically 80 percent. Many formulas divide by n − 1 to correct for bias.
4. Nitrogen
Science & Engineering · Chemical Element Abbreviations
Nitrogen, atomic number 7, makes up about 78% of Earth's atmosphere by volume as unreactive N2 gas. Plants cannot use it until it is fixed into ammonia or nitrates, which is why the Haber-Bosch process for synthetic fertilizer ranks among the most important industrial reactions. Liquid nitrogen boils at -196 °C.
Example: The bag's 20-10-10 analysis means 20% N, 10% phosphate and 10% potash by weight.
Daniel Rutherford isolated it in 1772 as "noxious air" that could not support a flame or a mouse. Jean-Antoine Chaptal coined nitrogène in 1790 from Greek nitron (saltpeter) and genes (forming); Lavoisier preferred azote, "lifeless," which survives in French and in chemical terms such as azide and azo dyes. The N in N-P-K fertilizer ratings is this element.
5. Noun (n.)
Writing & Everyday · Grammar and Dictionary Abbreviations
Labels a headword as a noun in dictionaries, glossaries and word lists, the part of speech that names a person, place, thing or idea. Learner's dictionaries often refine it into countable [C] and uncountable [U] nouns.
Example: bank (n.) 1. an organization that keeps and lends money; 2. the land along the side of a river
Merriam-Webster and the Oxford learner's dictionaries print "noun" in full, while compact and pocket dictionaries use n. Words used only in the plural, such as "scissors," are labeled n. pl. or pl. n. In citations, n. instead means a footnote, as in "p. 45 n. 3," so the setting separates the senses. In linguistic glossing the same letter can mark neuter gender.
6. Nano- (billionth) (n)
Units & Measurements · Metric and SI Unit Abbreviations
Billionth-scale prefix (10^-9), familiar from nanometers (light wavelengths and chip names), nanoseconds (computer timing) and nanograms (lab tests and pollutant limits).
Example: Visible light spans wavelengths from about 380 to 750 nm.
From Greek nanos, dwarf; adopted in 1960. Nanotechnology generally refers to structures between 1 and 100 nm. Computing pioneer Grace Hopper handed out pieces of wire about 30 cm long to show how far electricity travels in one nanosecond. Semiconductor names such as "3 nm" are now generation labels rather than measurements of any physical feature.
7. Population size (total sample size)
Units & Measurements · Statistics Abbreviations
Uppercase N denotes the number of units in a population or, in APA style, the total sample size of a study. Survey sampling formulas use N for the population and n for the sample.
Example: The final sample included N = 1,204 adults from 12 countries.
The finite population correction shrinks standard errors when the sample is a large fraction of the population. When N is much larger than n the correction is negligible, which is why a national poll of about 1,000 people is equally precise for small and large countries.
8. Note (n.)
Writing & Everyday · Citation and Bibliography Abbreviations · also used in law
Refers to a footnote or endnote in a citation or index, usually combined with a page number, as in "p. 45 n. 3." Indexes use it to show that a topic is discussed only in a note.
Example: Smith discusses the exception briefly in a footnote (p. 212 n. 14) but never returns to it.
The plural is nn. Chicago closes up page and note number in indexes, as in 45n3. Legal writers use the same device, as in "id. at 45 n.3." In dictionaries, n. means noun, so the setting separates the two.
9. Natural numbers
Units & Measurements · Math Abbreviations
The set of natural numbers, the counting numbers 1, 2, 3 and so on, usually written in blackboard bold as ℕ. Whether 0 is included varies: set theory and computer science usually include it, while number theory often does not.
Example: Prove that n² + n is even for every n in N.
Blackboard-bold letters began as a way to write bold type on a chalkboard. The international standard ISO 80000-2 includes 0 in ℕ and writes ℕ* for the positive integers. Related sets Z, Q, R and C form a chain of ever larger number systems.
Related abbreviations
More direction abbreviations
- ENE – East-northeast
- ESE – East-southeast
- GN – Grid north
- MN – Magnetic north
- NB – Northbound
- NE – Northeast
- NNE – North-northeast
- NNW – North-northwest
See all 23 direction abbreviations →