Angry with mother - but to a good end (3)
I believe the answer is:
mad
'angry' is the definition.
(similar in meaning)
'with mother but to a good end' is the wordplay.
'with' says to put letters next to each other.
'mother but' becomes 'ma' (Ma is another word for mother or mum. I am not sure about the 'but' bit.).
'end' indicates one should take the final letters.
The last letter of 'good' is 'd'.
'ma' next to 'd' is 'MAD'.
Can you help me to learn more?
(Other definitions for mad that I've seen before include "Crazy" , "Aberrant" , "lunatic" , "Roused to anger" , "Angry or insane" .)