Sami was involved in a drug syndicate.

All power to the syndicates!

The prize was divided equally among the ten syndicate members.

This sweet little old lady turned out to be the head of a crime syndicate.

Then these are your instructions, and I beg, my dear Watson, that you will obey them to the letter, for you are now playing a double-handed game with me against the cleverest rogue and the most powerful syndicate of criminals in Europe.