This is a charade - multiple separate elements are joined together in sequence to build the final answer.
Look for: 'papers' (think identification) reversed by 'back', plus the middle letters of 'glib', plus a word for 'man'. These three parts combine in order.
Answer: DILIGENT | ID (identification 'papers') reversed to DI + LI (middle letters of 'glib') + GENT ('man') = DILIGENT