conundrum /kə-nunˈdrəm/

1. A riddle, esp one whose answer is a play on words
2. Any puzzling question

• chromosomes
• chromosphere
• chromospheres
• chromospheric
• chromotherapies
• chromotherapy
• chromotype
• chromotypes
• chromotypography
• chromous
• chromoxylograph
• chromoxylographs
• chromoxylography
• chron-
• chron.
• Chron.
• chronaxie
• chronaxies
• chronic
• chronical
• chronically
• chronic fatigue syndrome
• chronicities
• chronicity
• chronicle