| fortuitous(adjective, happy, chance, fortunate, opportune) |
| casual(adjective, chance, random, lucky, unplanned) |
| random(adjective, chance, lucky, unplanned, accidental) |
| accidental(adjective, chance, lucky, unplanned, unpremeditated) |
| chance(adjective, lucky, unplanned, accidental, unpremeditated) |
| adventitious(adjective, happy, chance, fortunate, opportune) |
| lucky(adjective, fortunate, opportune, blessed, accidental) |
| happy |
| incidental(adjective, chance, lucky, unplanned, accidental) |
| unforeseen(adjective, chance, lucky, unplanned, accidental) |
| unexpected(adjective, chance, unplanned, unpremeditated) |
| unplanned(adjective, chance, lucky, accidental, unpremeditated) |
| aleatory |
| favorable(adjective, useful, beneficial, advantageous) |
| haphazard |
| symbiotic(adjective, useful, beneficial, advantageous) |
| unpremeditated(adjective, chance, unplanned) |
| arbitrary |
| opportune(adjective, happy, fortunate, blessed, fluky) |
| propitious(adjective, happy, fortunate, opportune, blessed) |