(attributive) (of a lens or microscope) having a layer of oil between the objective and the specimen so as to increase the numerical aperture.
Late 19th century; earliest use found in Nature: a weekly journal of science.
英汉双解词典包含464360条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。