I will get sick (3)
I believe the answer is:
ill
I believe this is a double definition.
'i will' is the first definition.
(I've seen this before)
'sick' is the second definition.
('ill' can be similar in meaning to 'sick')
'get' acts as a link.
(Other definitions for ill that I've seen before include "Imperfectly; unwell" , "Harmful" , "Not in good health" , "state, briefly" , "'Never speak . . . of the dead'" .)