bile
A bitter greenish-brown alkaline fluid secreted by the liver and stored in the gallbladder. / A feeling of intense anger, hatred, or bitterness.
[C/U] Both
In a medical sense, the word is neutral and technical, describing a necessary biological process. It evokes a sense of bitterness and acidity, which serves as the bridge to its psychological meaning.
Uncountable when referring to the biological fluid in the liver. Countable when referring to specific expressions of hatred or bitter remarks.