We usually just say the infirm or sick...


>>You said it: as a noun. IOW, there's no such noun in English.
>>
>>Sure there is.
>
>Haven't seen it in your message. Did it vanish together with the other medical slang reference? (I saw it - cute!)
>
>>That's not the same. Invalid is a disabled person - check in other languages.
>>
>>"Ill" eventually includes impairement/disablement in its definition, too. ;-)
>
>Eventually, maybe, but not from the outset. You don't get the status of an invalid for a flu, but you are ill, ergo bolesnik.