ADJ-GRADED
(天线、扩音器等)定向的
If something such as a radio aerial, microphone, or loudspeaker is directional, it works most effectively in one direction, rather than equally in all directions at once.
例句
Dish aerials are highly directional...
碟形卫星天线的定向性非常强。
The directional microphone trained on Foresters Cottage could pick up every word uttered inside at several hundred yards.
对准福雷斯特小屋的定向扩音器在几百码远的地方也能捕捉到里面的人所说的任何一句话。