Closed book
Synonyms for Closed book
- enigmapuzzlemysterybrain-teaser
- mysterypuzzlebrain-teaser
- riddlepuzzlemystery
- secret
- conundrumpuzzlemysterybrain-teaser
- brain-teaserpuzzle
- problempuzzlemysterybrain-teaser
- puzzlemysterybrain-teaser
- puzzlementbrain-teasermystery
- mystification
- poser
- why
- whodunit
- question
- crux
- teaser
- tough nut to crack
- quandary
- stumper
- thriller
- brainteaser
- subtlety
- secrecy
- dilemma
- perplexity
- braintwister
- mindboggler
- sphinx
- inscrutability
- oracle
For more similar words, try Closed book on Thesaurus.plus dictionary