Get progressively worse (11)
I believe the answer is:
deteriorate
(Other definitions for deteriorate that I've seen before include "Gradually worsen" , "Slip" , "Become steadily worse" , "Become slowly worse" , "Get worse" .)
I believe the answer is:
deteriorate
(Other definitions for deteriorate that I've seen before include "Gradually worsen" , "Slip" , "Become steadily worse" , "Become slowly worse" , "Get worse" .)