exact meaning of 'immunocompromised'

[David]

I'm actually translating some docs and I'd like to know the exact
translation of the word 'immunocompromised'...

Can you tell me if there is any difference between this wd and
'immunocompromission' and 'immunodeficiency' (of course, I don't assume
you to speak french, just try to describe it so I could have a precise
idea about it ;€)

thanks for advance

David
Paris