unconfirmed

As adjectives the difference between unconfirmed and undefined

is that unconfirmed is not finally established, settled or confirmed while undefined is lacking a definition or value.

As adjectives the difference between unconfirmed and impromptu

is that unconfirmed is not finally established, settled or confirmed while impromptu is improvised; without prior preparation, planning or rehearsal; extemporaneous; unplanned.

As a noun impromptu is

a short musical composition for an informal occasion often with the character of improvisation and usually to be played solo.

As adjectives the difference between unacknowledged and unconfirmed

is that unacknowledged is not acknowledged while unconfirmed is not finally established, settled or confirmed.

is likely misspelled.

has no English definition.

As an adjective unconfirmed

is not finally established, settled or confirmed.

As adjectives the difference between unconfirmed and nonconfirmed

is that unconfirmed is not finally established, settled or confirmed while nonconfirmed is unconfirmed.