Lacking tact or taste.
In a natural, untreated state.
Characterized by simplicity, especially something not carefully or expertly made.
Lacking concealing elements.
Pertaining to the uninflected stem of a word.
Any substance in its natural state.
Crude oil.
Insufficiently cooked, so as to be unpalatable or inedible.
Very lightly cooked.
The broccoli was nicely undercooked.
Done with insufficient energy, enthusiasm, etc.