tic-tac man

noun
1
a bookmaker(= a man who takes bets) at a horse racing course, who communicated information to other bookmakers there by means of tic-tac, a special language of signals involving movements of the hands and arms
دلال شرط‌بندی, کتاب‌ساز شرط‌بندی, کتاب‌ساز در مسابقه اسب‌دوانی