Very displeased with a useless railway (5)
I believe the answer is:
angry
'very displeased' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives can sometimes mean the same thing.
'with a useless railway' is the wordplay.
'with' says to put letters next to each other.
'a useless' becomes 'ang' (I can't justify this - if you can you should believe this answer much more).
'railway' becomes 'ry' (abbreviation for railway).
'ang'+'ry' is 'ANGRY'.
Can you help me to learn more?
(Other definitions for angry that I've seen before include "Very annoyed" , "In a temper" , "Furious" , "Irate, wrathful" , "In a paddy" .)