A Canadian's first coin, in a manner of speaking (6)
I believe the answer is:
accent
'a manner of speaking' is the definition.
(accent is a kind of manner of speaking)
'a canadian's first coin in' is the wordplay.
'canadian's first' becomes 'c' (1st letter of 'canadian').
'coin' becomes 'cent' (cent is a kind of coin).
'in' indicates putting letters inside.
'c' going into 'cent' is 'ccent'.
'a'+'ccent'='ACCENT'
(Other definitions for accent that I've seen before include "Stress - regional dialect" , "Distinctive manner of oral expression" , "Distinctive way of talking" , "Distinctive way of pronouncing language" , "Local way of pronouncing words" .)