tick-tacker n. at a horse track, a person (often a tout) who communicates information to others by hand signals. (source: Double-Tongued Dictionary)
Further reading
If someone tells you it’s flisky or flobby outside, do you need to take an umbrella? A new book about England’s soggy climate includes 188 terms for rainy weather. Americans have their own joking names for local weather, from June Gloom in Southern...
How do you transform ancient Chinese script for use in the modern age? English uses a keyboard with just 26 letters, but the first Chinese typewriter looked like a small table under a huge disk with more than 4,000 characters. A new book chronicles...