“Cheapjack” has a strange cast all round (6)

'cheapjack' is the definition.
(synonyms)
'a strange cast all round' is the wordplay.
'a strange' becomes 'odd' (I've seen this before).
'cast' becomes 'shy' (both can mean to throw or fling).
'all round' means one lot of letters goes inside another.
'odd' placed into 'shy' is 'SHODDY'.
'has' acts as a link.
(Other definitions for shoddy that I've seen before include "Cheap and poorly made" , "Of inferior workmanship" , "bits of waste material" , "poor quality fabric" , "Of poor quality or workmanship" .)
'round' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ton that I've seen before include "2,240 lbs" , "Fashionable" , "Century" , "100 mph, runs, etc" , "Two thousand - two hundred and forty pounds" .)
