Open English Wordnet
Adjectives
(s)debatable, problematic, problematicalopen to doubt or debate“If you ever get married, which seems to be extremely problematic”
(s)baffling, elusive, knotty, problematic, problematical, toughmaking great mental demands; hard to comprehend or solve or believe“a baffling problem”, “I faced the knotty problem of what to have for breakfast”, “a problematic situation at home”