1. having a harsh, disagreeably acrid taste, like that of aspirin, quinine, wormwood, or aloes.
2. producing one of the four basic taste sensations; not sour, sweet, or salt.
3. hard to bear; grievous; distressful: a bitter sorrow.
4. causing pain; piercing; stinging: a bitter chill.
5. characterized by intense antagonism or hostility: bitter hatred.
6. hard to admit or accept: a bitter lesson.
7. resentful or cynical: bitter words. noun
"battles can be bitterest."
"issues can be bitterest."
"conflicts can be bitterest."
"rivals can be bitterest."
"rhetorics can be bitterest."
This list can help you learn new vocabulary more quickly and be able explore other words more easily.