Here's a breakdown of its etymology:
* "doctrīna" (Latin) - teaching, instruction
* "docēre" (Latin) - to teach
* "disco" (Latin) - to learn
So, the word "doctrine" has its roots in the idea of teaching and learning, ultimately coming from the Latin verb "docēre" meaning "to teach." It has evolved to refer to a set of beliefs or principles taught by a particular group, person, or system.