noun
semiformal attire; semiformal dress
Refers to attire that is less formal than full formal wear but still appropriate for ceremonies, parties, or business occasions. Often contrasted with 正礼装 (formal attire) and 平服 (casual wear).
パーティーのドレスコードは略礼装です。
The dress code for the party is semiformal attire.
略礼装でお越しください。
Please come in semiformal dress.
平服 is casual wear, much less formal than 略礼装.
Compound of 略 (ryaku, 'abbreviated') and 礼装 (reisō, 'formal attire'), literally 'abbreviated formal wear'.