From Bouvier's Law Dictionary, Revised 6th Ed (1856) :
TICK, contracts. Credit; as, if a servant usually buy for the master upon tick, and the servant buy something without the master's order, yet, if the master were trusted by the trader, he is liable. 1 Show. 95; 3 Keb. 625; 10 Mod. 111; 3 Esp. R. 214; 4 Esp. R. 174.