threatening or foreshadowing evil or tragic developments; "a baleful look"; "forbidding thunderclouds"; "his tone became menacing"; "ominous rumblings of discontent"; "sinister storm clouds"; "a sinister smile"; "his threatening behavior"; "ugly black clouds"; "the situation became ugly"
deadly or sinister; "the Florida eagles have a fierce baleful look"
without careful prior deliberation or counsel; "ill-advised efforts"; "it would be ill-advised to accept the offer"; "took the unadvised measure of going public with the accusations"