ˈ ̷ ̷| ̷ ̷ ̷ ̷ adjective
: having the rib cage narrow from side to side with flat sides and the ribs deficient in lateral curvature
a slab-sided horse
also : giving an effect of such a condition by reason of leanness or slenderness
an airplane with a slab-sided fuselage
slab-sided cheeks