fixer

Short definition from Wiktionary

Noun

1. 1
   Agent noun of fix: one who, or that which, fixes.
2. 2
   A chemical (sodium thiosulfate) used in photographic development that fixes the image in place, preventing further chemical reactions.
3. 3
   A person who serves as an agent to arrange for a desired result, perhaps by improper and/or unlawful means.
4. 4
   Someone who is often paid that helps a customer cut through red tape, especially for government processes or applications.
5. 5
   A person who arranges immunity for defendants by tampering with the justice system via bribery or extortion, especially as a business endeavor for profit.
6. 6
   A person who assists foreign journalists in volatile countries, often providing interpretation, personal connections, and transportation services.
7. 7
   A fixer-upper.
8. 8
   A drug dealer or user.