Definition of uncertain
(adj)
lacking or indicating
lack of
confidence or assurance; "uncertain of his convictions"; "unsure of himself and his future"; "moving with uncertain (or unsure) steps"; "an uncertain smile"; "touched the ornaments with uncertain fingers"
not
certain to occur; not inevitable; "everything is uncertain
about the army"; "the
issue is uncertain"
ambiguous (especially in the negative); "she
spoke in no uncertain terms"