Substances produced by a plant or animal, often for a specific purpose such as protection or lubrication.
Secretions are usually thought of as something that comes out of a living thing and serves a useful purpose.
Examples:
The flower's secretions attract bees.
The snake's secretions can be poisonous.
I don't like the feel of the snail's secretions.
The dog's secretions make its fur shiny.
The plant's secretions help it stay healthy.
The bird's secretions protect its feathers.