I will shortly be unwell (3)
I believe the answer is:
I believe this is a double definition.
'i will shortly' is the first definition.
(abbreviation; 'shortly' suggests a short form)
'unwell' is the second definition.
(similar in meaning)
'be' is the link.
(Other definitions for ill that I've seen before include "Dicky" , "state of America" , "Not well, sick" , "Groggy" , "Where to find Chicago" .)