They had a strong appetency for reading. --Merivale.
2. Specifically: An instinctive inclination or propensity in
animals to perform certain actions, as in the young to
suck, in aquatic fowls to enter into water and to swim;
the tendency of an organized body to seek what satisfies
the wants of its organism.
These lacteals have mouths, and by animal selection
or appetency the absorb such part of the fluid as is
agreeable to their palate. --E. Darwin.
3. Natural tendency; affinity; attraction; -- used of
inanimate objects.