without a cap, with common uses referring to a fuel filler that doesn't require a separate gas cap, or a type of wig with an open-wefted, lightweight construction.
adjective [原级]无帽的;免盖的;无电容的
Research on Thermal Stress of Capless Rail with Ultrasonic Measurement 超声波检测无缝钢轨热应力研究
capless
“ -less” ⌜ 表示缺乏或没有某种特性 - indicating the absence or lack of a particular quality ~ ⌟