Definition of "semiformal"

The HLA defines the rules of interoperability, a semiformal methodology for specifying simulation and federation object classes, and the interface specification that is a precise specification of the functional actions that a simulation may invoke.

2006, Stanislaw Raczynski, Modeling and Simulation: The Computer Science of Illusion, page 31

When wearing the dragon robe on semiformal occasions, a single necklace was appropriate. Only the empress or empress dowager could wear a main necklace formed of Manchurian pearls, the other two being made of coral.

2007, Valery Garrett, Chinese Dress: From the Qing Dynasty to the Present, page 40

Suits have largely replaced guayabera shirts as business and semiformal wear for middle and upper-class Panamanian men, made practical by the widespread use of air-conditioning in the cities.

2005, Williams Friar, Panama, 1st edition, Emeryville, C.A.: Moon Handbooks, page 528

The skirt was way too short, at least shorter than she preferred. It left exposed a good eight inches between her knee and thigh. But what choice did she really have? Casual cropped pants were hardly appropriate attire for a semiformal event.

2006, Marcia King-Gamble, Designed for You, New York, N.Y.: Kimani Press, page 32

Bright-colored flyers decorated battered lockers, telling everyone to join the debate team, try out for the school play, and not to miss the fall semiformal this Friday. I wondered what a "semiformal" consisted of at a public school, not that I'd bothered to ask anyone.

2010, Amanda Hocking, Switched (Trylle Trilogy; 3), New York, N.Y.: St. Martin's Griffin, published 2012, page 9