Chart the French acer (5)
I believe the answer is:
maple
'acer' is the definition.
(I know that acer can be written as maple)
'chart the french' is the wordplay.
'chart' becomes 'map' (synonyms).
'the french' becomes 'le' ('the' in French).
'map'+'le'='MAPLE'
(Other definitions for maple that I've seen before include "Emblematic tree of Canada" , "----- leaf: symbol of Canada" , "Tree providing syrup" , "Ample sort of tree" , "Tree: its leaf the Canadian emblem" .)