discip- +

(Latin: discipulus, pupil, apprentice; instruction, teaching, learning (to learn), knowledge)

indisciplinable (adjective)
Incapable of being disciplined; not amenable to discipline; intractable: "No matter how much his parents tried, he was an indisciplinable child."
interdisciplinary, pluridisciplinary (adjectives)
Of or pertaining to two or more disciplines or branches of learning: "The student was contributing to and benefiting from three interdisciplinary areas of study."
multidisciplinary, multidiscipline
Studying or using several specialized subjects or skills.
multidisciplined
Combining many academic approaches, fields, or methods.
Non scholae, sed vitae discimus. (Latin statement)
Translation: "We do not learn just for school, but we learn for life." -Seneca, Jr.
Qui docet discit.
He who teaches learns.

Whenever a teacher prepares lessons for pupils/students, he/she can not help but learn; that is, if she/he actually prepares the materials.

To put it another way, "The best way to learn a subject is to teach it." Every dedicated teacher knows the truth of this proverb.

transdisciplinary
Of or pertaining to more than one discipline or branch of learning; interdisciplinary.
undisciplined
Not subjected to discipline; untrained.

Inter-related cross references, directly or indirectly, involving word units meaning "know, knowledge; learn, learning": cogni-; gno-; histor-; intellect-; learn, know; math-; sap-; sci-; sopho-.