unplanned

As a noun accident

is an unexpected event with negative consequences occurring without the intention of the one suffering the consequences.

As an adjective unplanned is

unintentional; not intended.

As an adjective unplanned

is unintentional; not intended.

As a verb improvise is

.

As adjectives the difference between unplanned and improvised

is that unplanned is unintentional; not intended while improvised is created by improvisation; impromptu; unrehearsed.

As a verb improvised is

simple past and past participle of improvise .

As adjectives the difference between adventitious and unplanned

is that adventitious is from an external source; not innate or inherent, foreign while unplanned is unintentional; not intended.

Unplanned is a related term of fortuitous.

As adjectives the difference between unplanned and fortuitous

is that unplanned is unintentional; not intended while fortuitous is happening by chance; coincidental or accidental.

As adjectives the difference between arbitrary and unplanned

is that arbitrary is (usually|of a decision) based on individual discretion or judgment; not based on any objective distinction, perhaps even made at random while unplanned is unintentional; not intended.

As a noun arbitrary

is anything arbitrary, such as an arithmetical value or a fee.

As adjectives the difference between disorderly and unplanned

is that disorderly is not in order; marked by disorder or disarray while unplanned is unintentional; not intended.

As adjectives the difference between unintended and unplanned

is that unintended is not intended; unplanned while unplanned is unintentional; not intended.

As adjectives the difference between unusual and unplanned

is that unusual is unlike what is expected; differing in some way from the norm while unplanned is unintentional; not intended.

As adjectives the difference between unplanned and unscheduled

is that unplanned is unintentional; not intended while unscheduled is not scheduled; impromptu.