directionn.方向；指导；用法说明；趋势；目标；管理directional gain定向系数,指向性增益,指向性指数directional gyro陀螺方向仪directionfindingn.方位测定directional word方位词direction cosine方向余弦directional unit定向器direction effect方位效应direction button控制系统按钮directional tire方向性轮胎,V形纹轮胎directional loop定向环形天线