Monthlong, as the name implies, refers to a period of one month long. On the opposite end of the spectrum, we have words that describe periods shorter than a month, called antonyms. Some antonyms for monthlong include spontaneous, brief, fleeting, momentary, ephemeral, and temporary. These words indicate a transitory, irregular, or unexpected duration, highlighting a contrast to something lasting for an entire month. For example, a spontaneous weekend trip, a brief moment of happiness, a fleeting emotion, or a temporary change can all be antonyms to the word monthlong. By understanding the antonyms of monthlong, we can better express the duration and nature of different experiences.