Synonyms of unforeseen

2 Syllables
unmeant, chanced, startling, fluctuant, abrupt, casual, chancing, chancer, sudden, zillion
3 Syllables
surprise, contingent, subito, fortuitous, surprising, suddenness, unfixed, lucky-dog
4 Syllables
unintended, unlooked-for, unpredicted, undesigned, uncountable, accidental, unexpected
5 Syllables
incomputable, unreckonable, incalculable, unintentional, uncalculated, unimagined, precipitousness
6 Syllables
unanticipated