Cry from one trapped by machinery (6)
I believe the answer is:
plaint
'cry' is the definition.
(thesaurus)
'one trapped by machinery' is the wordplay.
'one' becomes 'I' (Roman numeral).
'trapped by' indicates putting letters inside.
'machinery' becomes 'plant' (I've seen this before).
'i' going inside 'plant' is 'PLAINT'.
'from' is the link.
(Other definitions for plaint that I've seen before include "Accusation; charge" , "Legal suit" , "Archaic word for grievance (6)" , "Dirge" , "Cry of sorrow or grief" .)