S: (n) component, constituent, element (an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system)
S: (n) chemical element, element (any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter)
S: (n) element (the most favorable environment for a plant or animal)