Use 'unforeseeable' for unexpected events that couldn't be planned for, emphasizing the element of surprise. Due to unforeseeable weather conditions, the match was postponed.
Pro Tip 2/3
Not Always Negative
'Unforeseeable' doesn't only apply to bad outcomes; positive surprises also qualify. The startup's success was unforeseeable but welcome.
Pro Tip 3/3
Formality Use
'Unforeseeable' is formal and often used in official or business contexts, though it's fine in casual talk too. The contract has a clause to cover unforeseeable events.