Global body, one old and new, that might represent workers (5)
I believe the answer is:
union
'might represent workers' is the definition.
I can't tell whether this definition defines the answer.
'global body one old and new' is the wordplay.
'global body' becomes 'UN' (United Nations).
'one' becomes 'i' (Roman numeral).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'and' is a charade indicator (letters next to each other).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'un'+'i'+'o'+'n'='UNION'
'that' is the link.
Can you help me to learn more?
(Other definitions for union that I've seen before include "Trade organisation to represent workers" , "pearl amongst Shakespeareans" , "workers' co-operative" , "(Pipe) coupling" , "Organisation of employees formed to bargain with the employer" .)