0 a system in which tips (= extra money that customers give) are collected together and shared out among all the staff in a restaurant:
The company keeps only the 1 per cent it costs to process credit cards and run the tronc.
If a bill comes to £100, there is a discretionary service charge of £12.50. Of that, £10 goes to the company and £2.50 goes to the front of house via a tronc system.
