Synonyms for Middleman (same or very similar meaning)
WordNet sense 1 (someone who buys large quantities of goods and resells to merchants rather than to the ultimate customers):
jobber, wholesaler
WordNet sense 2 (the performer in the middle of a minstrel line who engages the others in talk):
interlocutor
WordNet sense 3 (a person who is in a position to give you special assistance):
contact, contact
From the ODE community, based on WordNet
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