Asterismal is a relatively obscure word, meaning "pertaining to asterisms" or patterns of stars in the sky. However, there are several synonyms that can be used in its place to describe the same concept. Some possibilities include constellation-related terms like stellar or sidereal, or more poetic adjectives like starry or celestial. Additionally, words like galactic or cosmic might capture the broader scope of space-related imagery that asterismal implies. Though not commonly used in everyday conversation, these synonyms can lend a sense of wonder and cosmic grandeur to writing about the night sky.