Definition of crossback:
(n) :
Two pieces on the back of an item (for attaching or bracing it) which form an "X".
(n) :
An "X"-shaped railroad crossing sign.
(n) :
(American football) A play in which the player with the ball crosses to one side of the field and then doubles back to the other.
(n) :
(dance) A step in which one leg crosses behind the other.
(n) :
The measurement from the outer edge of one shoulder blade to the outer edge of the other.
(n) :
A species resulting from such a crossback.