Merriam-Webster Collegiate Dictionary - rudiment

 noun  Etymology: Latin ~um beginning, from rudis raw, rude  Date: 1548  1. a basic principle or element or a fundamental skill — usually used in plural teaching themselves the ~s of rational government — G. B. Galanti  2.  a. something unformed or undeveloped ; beginning — usually used in plural the ~s of a plan  b.  (1) a body part so deficient in size or structure as to be entirely unable to perform its normal function  (2) an organ just beginning to develop ; anlage  • ~al adjective