Dash can get shortened (5)
I believe the answer is:
tinge
'dash' is the definition.
(thesaurus)
'can get shortened' is the wordplay.
'can' becomes 'tin' ('tin' can be a synonym of 'can').
'shortened' means to remove the last letter.
'get' with its last letter removed is 'ge'.
'tin'+'ge'='TINGE'
(Other definitions for tinge that I've seen before include "Hint; shade" , "A smack" , "Slight trace; colour" , "Colour slightly; trace" , "A shade or a nuance" .)