Lateral

Lateral: An anatomical direction that refers to a structure further from the midline of the body. For example, the anterior deltoid is lateral to the pectoralis major.

• Note that "midline" in this definition refers to a line through the middle of the body when the body is facing front or back in the anatomical position. That is a line that would bisect the body into left and right halves, also known as the mid-sagittal line. Lateral would be further from the mid-sagittal line.
  

The opposite of lateral:

• Medial

For more information on the anatomical directions, check out:

• Lesson 1: Anatomical Position and Anatomical Directions

Here is a list of anatomical structures with the word "lateral" included in their name:

• Lateral Deltoid: The most "lateral" of the 3 heads of the deltoids . This head of the deltoid contributes to shoulder abduction, as seen in a "lateral raise."
• Lateral Gastrocnemius: The lateral head of the more superficial and two-headed muscle of the calf, known as the gastrocnemius . Note that there is also a "medial head" of the gastrocnemius.
• Lateral Collateral Ligament (LCL): The lateral collateral ligament aids in the stabilization of the "outside" of the knee and prevents the tibia from adducting in the frontal plane. Note, that the medial collateral ligament stabilizes the "inside" of the knee.