rudimentary

英[,ruːdɪ'ment(ə)rɪ] 美[,rudɪ'mɛntri]

1. being or involving basic facts or principles;

"the fundamental laws of the universe"

"a fundamental incompatibility between them"

"these rudimentary truths"

"underlying principles"

2. being in the earliest stages of development;

"rudimentary plans"

3. not fully developed in mature animals;

"rudimentary wings"