Definitely make you take the wrong train (3,7)
I believe the answer is:
for certain
'definitely' is the definition.
(for certain means definitely or absolutely)
'you take the wrong train' is the wordplay.
'you take' becomes 'force' (I am not sure about this - if you are sure you should believe this answer much more).
'the wrong' indicates anagramming the letters.
'train' anagrammed gives 'rtain'.
'force'+'rtain'='FOR CERTAIN'
'make' is the link.
Can you help me to learn more?
(Other definitions for for certain that I've seen before include "surely" , "without a doubt" , "Assuredly" , "definitely" .)