Tough one synonyms | nouns

Synonyms for Tough one as a Noun

• puzzle
• conundrum
• riddle
• vexed question
• mystery
• puzzler
• enigma
• teaser
• difficult question
• awkward problem
• dilemma
• toughie
• stumper
• brainteaser
• problem
• question
• brain-teaser
• knotty point
• knotty problem