Upright gets corroded after time (6)
I believe the answer is:
trusty
'upright' is the definition.
Both the definition and answer are adjectives. Perhaps you can see a link between them that I can't see?
'corroded after time' is the wordplay.
I cannot really understand how this works, but
'corroded' could be 'rusty' (I've seen this in another clue) and 'rusty' is located in the answer.
'time' could be 't' (abbreviation) and 't' is present in the answer.
No letters remain.
This explanation may well be incorrect...
'gets' is the link.
Can you help me to learn more?
(Other definitions for trusty that I've seen before include "Staunch" , "Trainee officer" , "Reliable, faithful" , "Reliable, well-behaved prisoners with privileges" , "Reliable, honest and firm" .)