Bitterly is a word that is commonly used to describe an emotion that is characterized by anger, disappointment or sadness. However, this word can become overused, and at times it can be challenging to find the perfect synonym to convey the desired meaning. Some suitable synonyms for the word bitterly include indignantly, resentfully, ruefully, harshly, acrimoniously, venomously or acridly. These words can help to expand your vocabulary, making your writing more precise and engaging. It is always crucial to look for alternative words that are suitable in the context of the sentence and help to enrich your writing. By using a variety of synonyms, you can dictate a more vivid and compelling story.