Evergreen terrain includes log (5)
I believe the answer is:
enter
'log' is the definition.
(as in logging or entering information to a record)
'evergreen terrain includes' is the wordplay.
'includes' indicates a hidden word.
'ENTER' is hidden in the letters of 'evergreen terrain'.
(Other definitions for enter that I've seen before include "Introduce" , "Break in" , "Go in - set down" , "Go/come in" , "cross the threshold" .)