intelligence A2

/ɪnˈtɛl.ɪ.d͡ʒəns/ The ability to learn, understand, and think clearly.

intelligencer C2+

/ɪnˈtɛlɪdʒənsɚ/ one who conveys news or secret information; an informer or spy (archaic)

intelligentsia C2+

/ɪnˌtɛləˈdʒɛntsiə/ the class of educated people engaged in cultural and political ideas