凸とっ鏡きょう

noun

convex mirror

A mirror with a surface that curves outward, used for wider viewing angles, such as in road safety mirrors or store security mirrors.

• 交こう差さ点てんの凸とっ鏡きょうで後うしろから来くる車くるまを確かく認にんした。

  I checked for cars coming from behind using the convex mirror at the intersection.