uncertain
accidental
adventitious
aleatory
casual
causeless
chance
chancy
contingent
destinal
dicey
fatal
fatidic
fortuitous
iffy
incidental
indeterminate
odd
risky
uncaused
undetermined
unexpected
unforeseeable
unforeseen
unlooked-for
unpredictable
flukier
flukiest
5-speed
chem
durin
dust storm
free-to-air
gale-force
it'sa
microstrip
non-executive
protean
sou'west
southwesterly
suit-to-suit
superluminal
test-timer
unscrambled
vary
wide-beam