Problem: Who became Emperor of Rome after Tiberius?
Answer: caligula

Problem: What is the national flower of Scotland?
Answer: thistle

Problem: How are Oldham born comedy duo Thomas Derbyshire and Robert Harper known professionally?
Answer: cannon ball

Problem: What is an early sacrificial move in chess, usually of a pawn, to gain advantage, which has entered language with similar wider meaning?
Answer:
gambit