Clue: For starters in trigonometry, 100 radians equal 83? (5)
Answer: THREE
Explanation: Definition: 3
First letters ('for starters') of '**T**rigonometry' plus **H**undred ('100') plus **'R**adians' plus '**E**qual' plus **E**ight ('8'). And, yes, the definition is there, hiding next to the question mark (it does not get underlined). Qaos finds yet another version of the wonky arithmetic clue.