Smart Definition
Etymology
Pronunciation
semáforo
traffic light
sema-
sign
+
-foro
bearer
Semáforo means traffic light and can be thought of as a sign0 (sema-0) bearer1 (-foro1), which is exactly what a traffic light does.
noun
  1. traffic light
    A set of colored lights used to control traffic
    Detente cuando el semáforo esté en rojo. // Stop when the traffic light is red.