semiformal
1. [ adjective ] moderately formal; requiring a dinner jacket
Synonyms: semi-formal black-tie
Examples:

"he wore semiformal attire" "a black-tie dinner"

Related terms: formal
2. [ adjective ] moderately formal; requiring a dinner jacket
Synonyms: black-tie semi-formal
Examples:

"he wore semiformal attire" "a black-tie dinner"

Related terms: formal
Similar spelling:   semi-formal
  semipermeable