Pernicious (7)
(Other definitions for baleful that I've seen before include "Of evil influence" , "Menacing - gloomy" , "Threatening or foreshadowing evil" , "Menacing - vindictive" , "Malevolent" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pernicious</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that pernicious can be written as baneful)</span><br/ ><br/ >This is the entire clue.<br/ ></span>