Know how to use "fewer" and "less"? Find out.
"having no definite aim or purpose," 1650s, from at random (1560s), "at great speed" (thus, "carelessly, haphazardly"), alteration of Middle English noun randon "impetuosity, speed" (c.1300), from Old French randon "rush, disorder, force, impetuosity," from randir "to run fast," from Frankish *rant "a running" or some other Germanic source, from Proto-Germanic *randa (cf. Old High German rennen "to run," Old English rinnan "to flow, to run;" see run (v.)).
In 1980s U.S. college student slang it began to acquire a sense of "inferior, undesirable." (A 1980 William Safire column describes it as a college slang noun meaning "person who does not belong on our dormitory floor.") Random access in reference to computer memory is recorded from 1953. Related: Randomly; randomness.
1. Unpredictable (closest to mathematical definition); weird. "The system's been behaving pretty randomly."
2. Assorted; undistinguished. "Who was at the conference?" "Just a bunch of random business types."
3. (pejorative) Frivolous; unproductive; undirected. "He's just a random loser."
4. Incoherent or inelegant; poorly chosen; not well organised. "The program has a random set of misfeatures." "That's a random name for that function." "Well, all the names were chosen pretty randomly."
5. In no particular order, though deterministic. "The I/O channels are in a pool, and when a file is opened one is chosen randomly."
6. Arbitrary. "It generates a random name for the scratch file."
7. Gratuitously wrong, i.e. poorly done and for no good apparent reason. For example, a program that handles file name defaulting in a particularly useless way, or an assembler routine that could easily have been coded using only three registers, but redundantly uses seven for values with non-overlapping lifetimes, so that no one else can invoke it without first saving four extra registers. What randomness!
8. A random hacker; used particularly of high-school students who soak up computer time and generally get in the way.
9. Anyone who is not a hacker (or, sometimes, anyone not known to the hacker speaking). "I went to the talk, but the audience was full of randoms asking bogus questions".
10. (occasional MIT usage) One who lives at Random Hall. See also J. Random, some random X.