Definition of Rudimentary

Adjective: rudimentary  ,roo-du'men-t(u-)ree

  1. Being or involving basic facts or principles
    "these rudimentary truths";
    - fundamental, underlying
     
  2. Being in the earliest stages of development
    "rudimentary plans"
     
  3. (biology) not fully developed in mature animals
    "rudimentary wings";
    - vestigial

See also:
rudimentariness
rudiments