answer:Unpredictable, unforeseen, odd, unexpected, coincidental, not following a logical path…. That’s along the lines of how I’d interpret “random”. My Mac OS X Thesaurus says: random spot checks unsystematic, unmethodical, arbitrary, unplanned, undirected, casual, indiscriminate, nonspecific, haphazard, stray, erratic; chance, accidental. antonym systematic.