semiformal
se·mi·for·mal
adjective
1.
moderately formal; requiring a dinner jacket
- “he wore semiformal attire”
- “a black-tie dinner”
Origin
From semi- + formal.
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.