Effacé is classical ballet term meaning “shaded.” The term describes another step or pose in which the legs looks open, or not crossed, when seen from the front. You can say that effacé is the opposite of croisé.
A dancer can perform a step effacé devant or derriére, and either à terre (on the floor) or en l’air (off the floor). For example, a tendu effacé devant with the right as the working leg would have the dancers front leg in a tendu position to the front right corner. A dégagé effacé derriére, now with the left as the working leg, would face the same right corner with their left leg in the air so the legs look open.