unsplendid
/ˌʌnsˈplɛndɪd/Definitions
1. adjective
lacking splendor or grandeur; unimpressive
“The fireworks failed to live up to expectations, appearing unsplendid in the night sky.”
2. adverb
in a way that lacks splendor or grandeur; unimpressively
“She performed unsplendidly at the school talent show.”