Weary, with anger at heart (5)
I believe the answer is:
tired
'weary' is the definition.
(similar in meaning)
'with anger at heart' is the wordplay.
'with' means one lot of letters goes inside another.
'anger' becomes 'ire' (synonyms).
'at heart' becomes 'td' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ire' inserted inside 'td' is 'TIRED'.
Can you help me to learn more?
(Other definitions for tired that I've seen before include "getting bored" , "Played out" , "Zonked" , "Whacked" , "In need of sleep" .)