Normal displacement refers to the movement or shift of an object or particle in a perpendicular direction to a surface or plane. Synonyms for normal displacement include normal force, vertical displacement, perpendicular motion, and orthogonal displacement. Normal force is often used in physics and refers to the force exerted by a surface on an object in a direction perpendicular to the surface. Vertical displacement is commonly used in geology and refers to the up and down movement of rocks or soil layers. Orthogonal displacement is a more technical term used in mathematics and physics, referring to a vector that is perpendicular to another vector or plane. Synonyms for normal displacement can vary depending on the context and field in which they are used.