n. [generalized from J. Random Hacker]
Arbitrary; ordinary; any one; any old. 'J. Random' is often
prefixed to a noun to make a name out of it. It means roughly
'some particular' or 'any specific one'.
"Would you let J. Random Loser marry your daughter?"
The most common uses are 'J. Random Hacker', 'J. Random Loser', and 'J. Random Nerd'
("Should J. Random Loser be allowed to gun down other
people?"), but it can be used simply as an elaborate version of random in any sense.