ru·di·men·ta·ry 
(r′də-mĕntə-rē, -mĕntrē)
(r′də-mĕntə-rē, -mĕntrē)adj.
1. Of or relating to basic facts or principles; elementary: I have only a rudimentary knowledge of Greek.
2. Being in an early stage of development or having a simple form: traveled upriver in a rudimentary boat.
3. Biology Imperfectly or incompletely developed: a mutant mouse with rudimentary claws.
ru′di·men·tari·ly (-târə-lē) adv.
ru′di·menta·ri·ness n.