I need one word(or two) for somebody who has a problem. Any problem. For example, when the person to whom an address belongs (in a letter) is called an addressee(not entirely correct) So in similar terms, what's the person with a problem called?
As others have noted, I don't think there's a single word that covers all cases. It depends on the type of problem.
Often you use a word that describes the person's relationship to you regardless of the fact that they have a problem. Like if it's a customer complaining about bad service or defective products, you generally just call them the "customer". If it's a user of a computer system they are "the user". Etc.
If the problem has reached the point where the person is bringing a lawsuit, they are "the plaintiff".
If it's a medical problem: "patient". Occassionally, "the afflicted".
If the person is making a complaint, you can call them the "complainant", but I think that's pretty rare.
If the problem is caused by someone else and you want to place blame, you can say "the victim". That isn't necessarily limited to a crime, like you can say "the victim in the automobile accident".
I don't know a word the matches in general.
But in some contexts you can describe him with words that fits the situation. For instance:
If the problem faces him to a challenge you can call him challenger or contender.
If the situation is very unlucky for him you can call him unlucky fellow.
A little bit more general term may be:
- person affected
- person concerned
You might consider someone with a problem to be unfortunate, in which case you could call them an unfortunate.
unfortunate noun - an unfortunate person.
So you could say
This unfortunate has a problem.
It depends greatly on what the "problem" is. If the "problem" is in the sense of a person with a technical problem you might be able to use something like "Dear User:" If, instead, you mean a person with mental or physical deformities, malfunctions or diseases you'd better stick with "Dear Sir:/Dear Madam:" or something similar.