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."
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!
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".