fluky (adj.)

• accidental
• adventitious
• aleatory
• casual
• causeless
• chance
• chancy
• contingent
• dicey
• fatal
• fortuitous
• iffy
• incidental
• indeterminate
• odd
• risky
• uncaused
• undetermined
• unexpected
• unforeseeable
• unforeseen
• unlooked-for
• unpredictable