bitter

1 - Taste enables us to differentiate between bitter, sweet, salty or sour flavors.

2 - If every regrettable thing we did became part of a permanent social record, we'd all end up bitter and friendless.

3 - Not to trust is abnormal and is the natural result of bitter or even traumatic life experiences.

4 - 19th century scientists fell into a bitter debate as to whether intelligence lay in anatomy or a vital force was responsible for thoughts.

5 - Researchers concluded that a specific gene may cause some people to be particularly sensitive to the taste of broccoli, brussels sprouts, cabbage and other bitter-tasting veggies.