IPA: /ʌnˈdɒktrɪnɛə/
KK: /ʌnˈdɑktrəˌnɛr/
Not rigidly adhering to a particular doctrine or set of beliefs; open to different ideas and perspectives.
The professor's approach to teaching was undoctrinaire, encouraging students to think critically and explore various viewpoints.
Undoctrinaire → It is formed from "un-" (meaning not) and "doctrinaire" (from French, meaning a person who is dogmatic or adheres strictly to a doctrine). The word "undoctrinaire" means not adhering to a strict doctrine or being open to different ideas.
Think of 'not' ('un-') being applied to someone who is dogmatic ('doctrinaire'), which helps you remember that 'undoctrinaire' refers to someone who is open to various ideas rather than sticking rigidly to one doctrine.