“商务休闲装”常见的英文表达是 "business casual attire" 或 "business casual clothing"。
"business casual" 是固定搭配，指一种介于正式商务装（如西装）和完全休闲装（如T恤、短裤）之间的着装风格，常用于办公室、商务会议等需要一定正式度但不过于拘谨的场合。
"attire" 或 "clothing" 补充说明具体指服装。
例句：The company policy allows employees to wear business casual attire on Fridays.
（公司规定员工周五可穿商务休闲装。）
For the conference, please adhere to business casual clothing.
（会议请着商务休闲装。）