rudimentary
adj. C1 Advanced US //ˌɹudəˈmɛntɝi// UK //ɹˌuːdɪmˈɛntəɹi// rudi·men·ta·ry
adj. very basic or simple. You use this to describe something that is not fully developed or only covers the most important parts.
adj. relating to an immature, undeveloped, or basic form. Often describes skills, knowledge, or biological structures that are in an early stage of evolution or development.
He only has a rudimentary knowledge of French.
The early settlers built rudimentary shelters using only the branches and mud they found nearby.
While the species exhibits rudimentary social behaviors, it lacks the complex hierarchical structures observed in more advanced primates.
From rudiment + -ary.
Usage
Typically used to describe systems, skills, or physical structures; often carries a slightly negative tone if more complexity is expected.