Bit trashy but bashful without rum (6)
I believe the answer is:
shoddy
'bit trashy' is the definition.
I can't tell whether this definition defines the answer.
'bashful without rum' is the wordplay.
'bashful' becomes 'shy' (bashful means shy or reserved).
'without' is an insertion indicator ('without' can be similar in meaning to 'outside').
'rum' becomes 'odd' (rum can mean strange or dubious).
'shy' enclosing 'odd' is 'SHODDY'.
'but' is the link.
Can you help me to learn more?
(Other definitions for shoddy that I've seen before include "Badly made or done" , "Of poor quality or workmanship" , "Cheap and inferior" , "cheap material" , "Badly done; recycled fibre" .)