random

American  

[ran-duhm] / ˈræn dəm /

adjective

1. proceeding, made, or occurring without definite aim, reason, or pattern.

   the random selection of numbers.

   Synonyms:

   fortuitous, chance, haphazard

2. Statistics. of or characterizing a process of selection in which each item of a set has an equal probability of being chosen.

3. Building Trades.

   1. (of building materials) lacking uniformity of dimensions.

      random shingles.

   2. (of ashlar) laid without continuous courses.

   3. constructed or applied without regularity.

      random bond.

4. Slang.

   1. unknown, unidentified, or suspiciously out of place.

      A couple of random guys showed up at the party.

   2. odd or unpredictable, often in an amusing way.

      my totally random life.

---

noun

1. something that is random, or a random state or condition.

   different statistical methods used to estimate randoms.

2. Slang.

   1. a person or thing that is unknown, unidentified, or suspiciously out of place.

   2. a person or thing that is odd or unpredictable.

3. Chiefly British. bank.

adverb

1. Building Trades. without uniformity.

   random-sized slates.

idioms

1. at random, without definite aim, purpose, method, or adherence to a prior arrangement; in a haphazard way.

   Contestants were chosen at random from the studio audience.

random British  

/ ˈrændəm /

adjective

1. lacking any definite plan or prearranged order; haphazard

   a random selection

2. statistics

   1. having a value which cannot be determined but only described probabilistically

      a random variable

   2. chosen without regard to any characteristics of the individual members of the population so that each has an equal chance of being selected

      random sampling

3. informal (of a person) unknown

   some random guy waiting for a bus

---

noun

1. in a purposeless fashion; not following any prearranged order

random Scientific  

/ răn′dəm /

1. Relating to a type of circumstance or event that is described by a probability distribution.

2. Relating to an event in which all outcomes are equally likely, as in the testing of a blood sample for the presence of a substance.

---

random More Idioms  

1. see at random.

---

Other Word Forms

• nonrandom adjective
• nonrandomness noun
• randomly adverb
• randomness noun

Etymology

Origin of random

First recorded in 1275–1325; Middle English raundon, random, from Old French randon, derivative of randir “to gallop,” from Germanic

Example Sentences

For many years, biology textbooks have described protein movement inside cells as a largely random process called diffusion.

From Science Daily • Apr. 1, 2026

"It's kind of random, but it's kind of crazy," said her friend Sinead.

From BBC • Mar. 30, 2026

But often, they’re sources like Tripadvisor, Amazon reviews, or even random posts on niche subreddits.

From Slate • Mar. 28, 2026

He and his team selected 50 stocks at random from the 500 largest companies by market capitalization each month since 1999, assigning them equal starting weights.

From Barron's • Mar. 26, 2026

Washington was the core of gravity that prevented the American Revolution from flying off into random orbits, the stable center around which the revolutionary energies formed.

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis

Related Words

• accidental
• aimless
• arbitrary
• incidental
• indiscriminate
• irregular
• odd
• unplanned