Truck on edges of Canberra turned sharp (5)
I believe the answer is:
acute
'sharp' is the definition.
(I know that sharp can be written as acute)
'truck on edges of canberra turned' is the wordplay.
'truck' becomes 'ute' (Australian abbreviation for utility vehicle).
'on' says to put letters next to each other.
'edges of' says to hollow out the word (remove centre letters).
'turned' shows that the letters should be reversed in order.
'canberra' with its middle removed is 'ca'.
'ca' back-to-front is 'ac'.
'ute' after 'ac' is 'ACUTE'.
(Other definitions for acute that I've seen before include "Critical: shrewd" , "Sharp as of mind - or pain" , "Sharp; type of accent" , "Sharp; severe" , "(Of an angle) less than 90 degrees" .)