unobstructed
adj. 没有障碍的；畅通无阻的
反义词
参考例子
1.Are aisles between equipment and walls unobstructed?
设备与墙之间是否畅通无阻？
2.When our nostrils are unobstructed, we involuntarily alternate breathing through one or the other about every two hours.
当我们的鼻孔畅通时，我们每两小时就会不经意地用两个鼻孔交替呼吸。
3.Exits should be unblocked(from the inside), unobstructed and well marked. The exit door should push to open, not pull to open.
紧急出口需保持畅通，不得有任何阻挡/阻塞，且明显标示。紧急出口门必须是推开，而不是拉开。
英文解释
adj.
1.free from impediment or obstruction or hindrance
网络释义
unobstructed
没有障碍的; 无阻挡的; 开阔，无障碍的; 畅通无阻的;
unobstructed view
自由视野; 释义：自由视野;
unobstructed capacity
有效容积;
unobstructed counter
没有障碍的护栏;
unobstructed construction
无障碍结构; 无障碍结构（建筑物构件不影响洒水喷头控制火或灭火）;