submillimeterWiktionary 原文构词拆分sub-前缀Under, beneath. · Subsidiary, secondary.+millimeter词根/词干词源说明sub- + millimeter释义（英文）形容词 Adjective(sciences) Less than a millimeter in size.名词 Noun(sciences) A unit or measurement that is less than a millimeter.词族派生词（2）submillimeter galaxysubmillimeter wave radiation