【Sinister】 , 【baleful】 ,  【malign】 ,  【malefic】 ,  【maleficent】  all mean seriously threatening, portending, or promising evil or disaster, usually imminent or already initiated evil or disaster.

【Sinister】 is the most commonly employed of these words and the widest in its range of reference. It may be applied not only to something perceptible, but to something imperceptible.

In either case  【sinister】  often expresses a judgment based on experience or on an interpretation of outward signs and implies on the part of the observer a resulting fear or apprehension of approaching evil or of lurking dangers; thus, a cloud is describable as  【sinister】  when it has the color, shape, or general character of one that the observer believes to precede a tornado; a person’s influence may be interpreted as  【sinister】 when it is judged in the light of some of its visible effects.

【Sinister】 is also applied to something that works or operates so covertly, insidiously, or obliquitously that it is likely to find those whose well-being it threatens off guard.

【Baleful】  carries an even stronger suggestion of menace than  【sinister】 for it implies inevitable suffering, misery, or destruction; often it imputes perniciousness, noxiousness, or hellishness to the thing so described. It is applicable to something that works openly and without indirection as well as to something that works occultly or obliquely.

【Malign】  (see also MALICIOUS ) carries over from its earliest sense a suggestion of an inherently evil or harmful tendency or disposition, even though the term in this sense is characteristically applied to immaterial things (as appearances, aspects, forces, or influences) rather than to persons.

It also carries connotations (as of boding evil or disaster) derived from its reference in astrology to the aspects or the influences of the stars and occasionally suggests a force or power contributory to boded disaster.

【Malefic】  and  【maleficent】  carry a stronger suggestion of balefulness than does  【malign】 , for both regularly imply not only a tendency toward but an active force productive of evil or disaster; thus, a  【malign】  influence bodes disaster; a  【malefic】  or  【maleficent】 influence is putting the threat of disaster into effect.