The phrase "curl one lip at" means to express contempt or disgust, often by lifting one corner of the mouth. Some antonyms for this phrase could include smiling, grinning, chuckling, or laughing. When someone is amused or delighted by something, they are unlikely to curl their lip in disdain. Additionally, synonyms for the phrase might include sneering, smirking, or scoffing. Understanding antonyms and synonyms can help you better communicate your thoughts and feelings, and can make your writing more nuanced and interesting. By familiarizing yourself with these literary devices, you can create more dynamic and effective messages that truly connect with your audience.