a system of sign language, mainly using the hands, by which bookmakers transmit their odds to each other at racecourses
2. US
a ticking sound, as made by a clock
Word origin
from tick1
ticktack in American English
(ˈtɪkˌtæk) or ˈticˌtac (ˈtɪkˌtæk)
noun
1.
a recurring sound like the ticking of a clock
2.
a device for making a tapping sound on a windowpane or door as a prank: it consists typically of a weight hung next to the window, etc. and manipulated from a distance by a string