Dump at the roadside (5)
I believe the answer is:
ditch
'dump' is the definition.
(both can mean to discard)
'the roadside' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
The remaining letters 'dich' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'at' acts as a link.
Can you help me to learn more?
(Other definitions for ditch that I've seen before include "Dump; channel" , "Abandon - trench" , "Drainage trench" , "Throw away - trench" , "long depression" .)