Unremarkable or uninteresting; boring; uncool.
Elementary, simple, fundamental, merely functional.
Of or pertaining to a base; having a pH greater than 7.
Necessary, essential for life or some process.
An elementary building block, e.g. a fundamental piece of knowledge.
A necessary commodity, a staple requirement.
Basic training.
Insufficiently cooked, so as to be unpalatable or inedible.
Very lightly cooked.
The broccoli was nicely undercooked.
Done with insufficient energy, enthusiasm, etc.