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
Samantha Harvey’s novel Orbital is a sensuous, exhilarating meditation about the strangeness of life on a space station, with its mix of tedious tasks and jaw-dropping views. And: a musician who rode the rails in his youth shares the slang he...
Steve, a singer-songwriter from Rock Springs, Wyoming, shares some slang he picked up while months riding the rails and busking. Spanging refers to panhandling, from asking for “spare change.” The term bull refers to a type of security...