What is "semiformal"

Usage examples of "semiformal".

But there’s an enormous difference between the effects of a semiformal duel between consenting adults, with A-gate backups to make resurrection a minor headache, and cleaning up after a random act of senseless brutality in a Church parking lot.

As his callers entered the room, Underknuckle, a lean, high-shouldered man with bushy white hair, hollow, purplish cheeks, and a lumpy, clay-colored nose, his immaculately tailored midafternoon semiformal uniform awry, spun in his hip-u-matic contour chair, causing the power-swivel mechanism to whine in protest.