(noun) the exterior (outer), projecting part of a bird's mouth, composed of bone covered with a hard keratin shell.
(noun) a tree or shrub that grows in muddy, mainly tropical coastal swamps, and typically having numerous tangled roots above ground that form dense thickets.
(noun) the amount of energy expended in a given period.
(verb) the replacement of all or part of the feathers. Since feathers cannot heal themselves when damaged, they have to be completely replaced.
(noun) a change in the genes of a plant or animal that causes physical characteristics that are different from what is normal.