This is the 4058th most frequent Japanese word.
ビター
"Bitter."
The word 'ビター' is used as a description, mimicking the English word 'bitter,' referring to taste, depending on context.
このチョコレートはビターで、大人の味がします。
This chocolate is bitter, making it taste refined.
Here, 'ビター' modifies '冗談' (joke) to describe its nature, indicating a figurative bitterness or sharpness in humor.
彼のビターな冗談は、周りの人を戸惑わせました。
His bitter joke puzzled the people around him.
In this case, 'ビター' directly describes the flavor profile of the coffee, conveying a specific taste quality.