at random

WordReference Random House Learner's Dictionary of American English © 2025

ran•dom /ˈrændəm/   adj. 

1. occurring or done without definite aim, reason, plan, or pattern:
   a few random examples; random killings.
2. Statistics of or being a process of selection in which each item of a group has an equal chance of being chosen.

Idioms

3. Idioms at random, without regard to rules, schedules, purpose, pattern, etc.:
   chose colors at random.

ran•dom•ly, adv. 

WordReference Random House Unabridged Dictionary of American English © 2025

ran•dom  (ran′dəm), adj. 

1. proceeding, made, or occurring without definite aim, reason, or pattern:
   the random selection of numbers.
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
   • (of building materials) lacking uniformity of dimensions:
     random shingles.
   • (of ashlar) laid without continuous courses.
   • constructed or applied without regularity:
     random bond.

n. 

4. Printing, British Terms [Chiefly Brit.] bank³ (def. 7b).
5. 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.

adv. 

6. Building without uniformity:
   random-sized slates.

• Gmc
• Old French randon, derivative of randir to gallop
• Middle English raundon, random 1275–1325

ran′dom•ly, adv. 
ran′dom•ness, n. 
Synonyms

• 1. haphazard, chance, fortuitous.

Collins Concise English Dictionary © HarperCollins Publishers::

random / ˈrændəm/ adjective

1. lacking any definite plan or prearranged order; haphazard: a random selection
2. having a value which cannot be determined but only described probabilistically: a random variable
3. 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

noun

1. an unknown person or stranger
2. at random ⇒ in a purposeless fashion; not following any prearranged order

Etymology: 14th Century: from Old French randon, from randir to gallop, of Germanic origin; compare Old High German rinnan to run

ˈrandomly adverb

ˈrandomness noun