It depends on the level of formality. I think invalid is somewhat of an outdated term, more so constained to literature and other written text nowadays. However, depending on the context, I think it would not be impolilte as much as passé to call someone a sick person an invalid. (If you are looking for a word to substitute for the phrase 'a sick person,' though, invalid is probably the best word that exists) Hope this helps!
invalid person is that person who is sick. for example wheel chair person,handicaped person.
the little boy in the wheel chair is an invalid person. Invalid means sick, disabled, or diseased person
I think in this context it would mean "cooking for invalids" - invalid being an old-fashioned way of saying "unwell person". i.e it's a cookbook of what to feed ill people.
The meaning of the terms valid and invalid when applied to people can vary depending on how they are used. The word invalid can mean that a person is sick or has a disability. The term valid might mean that the person has an excellent career and family life.
a patient
Do you mean when you call on the phone? Of course not; that makes no sense at all.
=== === ---- === === this site is a bit vague
doctors
If he or she is sick,then the parish would call a priest to anoint him and pray for him for his healing.
healthy
Example: If someone is sick and they touch the phone and then you come and touch the phone to make a call and you don't know that the person is sick.... (that is how you get germs.)
Instigator, Agitator, Incendiary, and maybe Sick if they enjoy it.