Place is terribly significant (7)
I believe the answer is:
special
'significant' is the definition.
(thesaurus)
'place is terribly' is the wordplay.
'terribly' indicates anagramming the letters.
'place'+'is'='placeis'
'placeis' with letters rearranged gives 'SPECIAL'.
(Other definitions for special that I've seen before include "Particular, peculiar" , "An addition to the standard menu" , "Though particular" , "Day's non-menu dish" , "Dish not on regular menu" .)