Unlucky, disastrous, ill-starred, ill-fated, unfortunate, calamitous, luckless, hapless can all mean having, meeting, or promising an outcome that is distinctly unfavorable (as to hopes, plans, or well-being).
Unlucky implies that in spite of efforts or merits one meets with bad luck, often chronically, or that a specific occasion or action will be or has proved to be unfavorable especially in its outcome or consequences.
Disastrous and ill-starred both carry the astrological implication that the stars are adverse to the person or thing in question and both suggest a more or less dire fate for him or it.
Though disastrous and ill-starred often imply a calamitous result as inevitable disastrous is not infrequently used in a much weakened sense without a hint of inevitability or, often, an implication of consequences more serious than that of a turning of the tables upon one or the other of the participants or contenders.
Ill-starred, on the other hand, is close to ill-fated in meaning in that both imply an evil and unavoidable destiny awaiting a person or an action.
Unfortunate , though often interchangeable with unlucky , carries a much weaker implication of the intervention of chance <had an unfortunate day at the races> and a much stronger suggestion of misfortune, misery, unhappiness, or desolation, often to the extent of eliminating all suggestions of luck or of chance; occasionally it means nothing much more than regrettable or disastrous in its weakened sense.
Calamitous, which is used of events rather than persons, resembles unfortunate in its frequent elimination of all suggestion of luck or chance and in sometimes meaning little more than regrettable or upsetting , but it, like the noun calamity (which see under DISASTER ) often suggests dire misery or the utmost of woeful distress typically stemming from some grave and extraordinary event.
Luckless and hapless are more or less rhetorical terms implying that the person or thing so described has or reveals less than average good luck or good fortune (as in his undertakings or in their outcome); usually these words mean nothing more than unhappy , miserable , or wretched .