Not settled, uncertain, of uncertain outcome; debatable, questionable, open to doubt.
Difficult to overcome, solve, or decide.
Contributing (especially if subtly) to discrimination (such as racism, sexism, homophobia, transphobia, or ageism).
a problematic analysis
A problem or difficulty in a particular field of study.
Not yet resolved, finished, answered, decided or certain.
Used other than figuratively or idiomatically: see up, in, the, air.