With this, evidence of engagement seen in desert? (7)
I believe the answer is:
abandon
'desert?' is the definition.
('abandon' can be a synonym of 'desert')
'with this evidence of engagement' is the wordplay.
I cannot quite see how this works, but
'with' could be 'and' and 'and' is found in the answer.
'of' could be 'o' and 'o' is located in the answer.
This explanation may well be incorrect...
'seen in' is the link.
Can you help me to learn more?
(Other definitions for abandon that I've seen before include "Leave, desert" , "Give up (something) completely" , "Lack of inhibition; desert" , "Jack in" , "Desert, forsake" .)