Here's what rhymes with fortuitous.

Consider these alternatives

unfortunate / fortunate unforeseen / seen fortunate / unfortunate opportune / soon unsurprising / rising unexpected / rejected fluke / duke inopportune / soon fortuitously / circuitously inauspicious / wishes unforseen / seen masterstroke / spoke counterintuitive / intuitive juxtaposition / position implausible / plausible unanticipated / dated tantalizingly / surprisingly