Come in from hidden terrace (5)
I believe the answer is:
enter
'come in' is the definition.
(synonyms)
'from hidden terrace' is the wordplay.
'from' indicates the answer is hidden within the clue.
'ENTER' is hidden in the letters of 'hidden terrace'.
(Other definitions for enter that I've seen before include "Break in" , "Register formally as a participant" , "Make a record of" , "submit?" , "Register (as a competitor)" .)