You searched for: “andragogy
andragogy (s) (noun) (no pl)
Generally known as the method or technique used to teach adults: Mr. Jones was not interested so much in pedagogy, but in andragog because he thought he would get along with teaching grown-ups better than with teaching unruly children.

Andragogy is mistakenly used to refer to adult education for both men and women learners. “Mistakenly” because andro, -andra- refer only to males and not to women.

Another erroneous explanation is "the art and science of helping adults learn".