I've heard some people say someone was indisposed when they were busy and couldn't see or talk to me at the moment.
But actually indisposed really means that the person is slightly ill and not feeling good enough to really talk with you or see you.
I don't hear many people saying someone is indisposed because it's a really old saying but some older people will tell me someone is indisposed at the moment.
I used to work in an office making calls from a doctors office about appointments and sometimes the other spouse would answer the phone and I asked to speak to their wife and then the husband would say that she was indisposed at the moment.
Turns out he actually meant that she was just busy in the shower when I asked if she was ill because it was just a doctors appointment.