Definition of feather
(Entry 1 of 2)
Note: Feathers include the smaller down feathers and the larger contour and flight feathers. Larger feathers consist of a shaft (rachis) bearing branches (barbs) which bear smaller branches (barbules). These smaller branches bear tiny hook-bearing processes (barbicels) which interlock with the barbules of an adjacent barb to link the barbs into a continuous stiff vane. Down feathers lack barbules, resulting in fluffy feathers which provide insulation below the contour feathers.
Definition of feather (Entry 2 of 2)