The difference between Accessory and Supplement

Accessory as an adjective:

Having a secondary, supplementary or subordinate function by accompanying as a subordinate; aiding in a secondary way; being additional; being connected as an incident or subordinate to a principal; contributing or being contributory. Said of people and things, and, when of people, usually in a bad sense

Accessory as an adjective (legal):

Assisting a crime without actually participating in committing the crime itself.

Accessory as an adjective:

Present in a minor amount, and not essential.

Accessory as a noun:

Something that belongs to part of another main thing; something additional and subordinate, an attachment.

Accessory as a noun (fashion):

An article that completes one's basic outfit, such as a scarf or gloves.

Accessory as a noun (legal):

A person who is not present at a crime, but contributes to it as an assistant or instigator.

Accessory as a noun (art):

Something in a work of art without being indispensably necessary, for example solely ornamental parts.

Supplement as a noun:

Something added, especially to make up for a deficiency.

Supplement as a noun:

An extension to a document or publication that adds information, corrects errors or brings up to date.

Supplement as a noun:

An additional section of a newspaper devoted to a specific subject.

Supplement as a noun (geometry):

An angle that, when added to a given angle, makes 180; a supplementary angle.

Supplement as a noun (nutrition, bodybuilding):

A vitamin, herbal extract or chemical compound ingested to meet dietary deficiencies or enhance muscular development.

Supplement as a verb:

To provide or make a supplement to something.