To help you interpret things you might overhear, here is a brief summary of the descriptive terms that physicians use to describe exactly what they are talking about on the body.
anterior - in front of
posterior - behind
medial - toward the center of the body
lateral - away from the center of the body
distal - farther from the origin of a limb or from the center of the body
proximal - nearer to the origin of a limb or from the center of the body
volar - a toughie; imagine a man standing with arms at the sides, palms facing toward you - that is the volar surface of the arm
dorsal - back or rear of the body
ventral - underside or front side of the body
plantar - relating to the surface of the sole of the foot
palmar - relating to the surface of the palm
cephalad - toward the head
caudad - toward the "tail"
peri - around, as in periumbilical (around the belly button)
ipsi - the same, as in ipsilateral (same side)
contra - the opposite, as in contralateral (the other side)
infra - below, as in infraorbital ridge (bony ridge under the eye)
supra - above, as in supraorbital ridge (bony ridge above the eye)
intra - within, as in intraventricular (inside the ventricle)
extra - outside of, as in extravasate (to flow outside of the vessel)
flexor - the crease side of a limb, e.g. the crease side of the elbow, or on the leg, the side opposite the kneecap
extensor - the opposite side of the limb, e.g. the side of the elbow where you bump your funnybone
unilateral - on one side of the body
bilateral - on both sides of the body
I will think of some more when I can. It is getting late...