In turn it's consumed with decay (6)
I believe the answer is:
rotate
'in turn' is the definition.
'rotate' can be an answer for 'turn' (rotating is a kind of turning). I'm not sure about the 'in' bit.
'consumed with decay' is the wordplay.
'consumed' becomes 'ate' (to eat is to consume food).
'with' says to put letters next to each other.
'decay' becomes 'rot' (rot can mean to decay).
'ate' after 'rot' is 'ROTATE'.
'it's' is the link.
Can you help me to learn more?
(Other definitions for rotate that I've seen before include "Alternate" , "Turn around on axis or central point" , "Go around" , "Whisk round" , "wheel" .)