在英文中，试验室主任可以翻译为 "laboratory director" 或 "lab director."

"Laboratory" 是英文中指实验室的常用词，来自拉丁文 "laboratorium"，意思是 "a place for working, especially a place where scientific experiments are done."

"Director" 是指主管、负责人的意思，来自拉丁文 "director"，意思是 "someone who is in charge of something or someone."

下面是一些英文例句及其中文翻译：

The laboratory director is responsible for overseeing all research projects in the lab. (试验室主任负责监督实验室内的所有研究项目。)
The lab director is a highly skilled scientist with many years of experience. (试验室主任是一位高度熟练的科学家，有许多年的经验。)
The laboratory director is responsible for ensuring the safety of all lab personnel. (试验室主任负责确保所有实验室人员的安全。)