rudiment

Etymology

From Old French, from Latin rudimentum (“a first attempt, a beginning”), plural rudimenta (“the elements”), from rudis (“rude”); see rude.

noun

1. (often in the plural) A fundamental principle or skill, especially in a field of learning.
   We'll be learning the rudiments of thermodynamics next week.
2. (often in the plural) A form that lacks full or complex development.
   I have the rudiments of an escape plan.
   The single leaf is the rudiment of beauty in landscape. a. 1865, Isaac Taylor, Ornamentation of Nature
3. (biology) A body part that no longer has a function
4. (music) In percussion, one of a selection of basic drum patterns learned as an exercise.

verb

1. (transitive) To ground; to settle in first principles.