problematical (adj.)
- absurd
- arguable
- baffling
- confounding
- confusing
- confutable
- conjectural
- contestable
- controversial
- controvertible
- debatable
- deniable
- disconcerting
- dismaying
- disputable
- disturbing
- doubtable
- doubtful
- dubious
- dubitable
- embarrassing
- enigmatic
- iffy
- implausible
- inconceivable
- incredible
- intricate
- mistakable
- moot
- mysterious
- mystifying
- perplexing
- perturbing
- preposterous
- problematic
- puzzling
- questionable
- refutable
- ridiculous
- speculative
- suppositional
- suspect
- suspicious
- tall
- thick
- thin
- unbelievable
- unconvincing
- unearthly
- ungodly
- unimaginable
- unthinkable
- upsetting
