unimagined
adjective
[ ʌnɪˈmadʒɪnd ]
• not having been imagined or thought of as possible.
• "a previously unimagined degree of economic and social freedom"
Similar:
unthought of,
unpredicted,
unforeseen,
unanticipated,
unplanned,
accidental,
unlooked for,
unsought,
unexpected,
not bargained for/on,
sudden,
abrupt,
surprising,
startling,
astonishing,
abnormal,
out of the blue,