From Longman Dictionary of Contemporary Englishtipstertip‧ster /ˈtɪpstə $ -ər/ noun [countable] DSHsomeone who gives information about which horse is likely to win a race
Examples from the Corpus
tipster• My most pressing experience of Wigg as a tipster was on one of the rare occasions when I went to the Derby.• But we are not shirking our duty as tipsters.• The shares were coasting along at above 400p and looking like going better after a string of tipsters recommendations.• Dan Gardner later came forward and admitted that he was the tipster.• Readers' original gardening tips Another batch of £50 cash prizes are winging their way to this month's top tipsters.• On one hand, the prospect of a reward may draw out some otherwise wary tipsters. 