someone who is unfortunate has something bad happen to them:
When we entered the room, the teacher was yelling at some unfortunate student.
an unfortunate situation, condition, quality etc is one that you wish was different:
an unfortunate turn of events
He has an unfortunate habit of repeating himself.
it is unfortunate (that)
It's unfortunate that so few people seem willing to help.
It's most unfortunate (=very unfortunate) that your father can't come to the wedding.
happening because of bad luck:
unfortunate behaviour, remarks etc make people feel embarrassed or offended:
an unfortunate choice of words