Spy walks unevenly into empty garage (7)
I believe the answer is:
glimpse
'spy' is the definition.
(thesaurus)
'walks unevenly into empty garage' is the wordplay.
'walks unevenly' becomes 'limps' (walks with an injured leg).
'into' indicates putting letters inside.
'empty' means to remove the middle letters.
'garage' with its middle taken out is 'ge'.
'limps' going within 'ge' is 'GLIMPSE'.
(Other definitions for glimpse that I've seen before include "Quick view" , "Gander" , "Briefly catch sight of" , "A brief view or sighting" , "spot" .)