A problem or difficulty in a particular field of study.
Difficult to overcome, solve, or decide.
Contributing (especially if subtly) to discrimination (such as racism, sexism, homophobia, transphobia, or ageism).
Not settled, uncertain, of uncertain outcome; debatable, questionable, open to doubt.
a problematic analysis
A trusted person, especially a prisoner who has been granted special privileges.
Reliable or trustworthy.