Like greased lightning is an expression that refers to something or someone moving very quickly. Antonyms for this phrase include slow, sluggish, lethargic, and plodding. These words suggest a lack of speed or energy, indicating a slower pace than that of lightning. Alternatively, one can use other phrases that indicate speed such as "at breakneck speed," "like a bullet," or "in a flash." It's important to note that while the phrase "like greased lightning" has negative connotations when used to describe a person's behavior, its original meaning suggests something that is extremely fast, smooth, and efficient, like a well-lubricated machine.