Medium

Part of speech: noun (n.)

1. That which lies in the middle, or between other things; intervening body or quantity. Hence, specifically: (a) Middle place or degree; mean. The just medium . . . lies between pride and abjection. L'Estrange.

2. See Mean.

3. A substance through which an effect is transmitted from one thing to another; as, air is the common medium of sound. Hence: The condition upon which any event or action occurs; necessary means of motion or action; that through or by which anything is accomplished, conveyed, or carried on; specifically, in animal magnetism, spiritualism, etc., a person through whom the action of another being is said to be manifested and transmitted. Whether any other liquors, being made mediums, cause a diversity of sound from water, it may be tried. Bacon. I must bring together All these extremes; and must remove all mediums. Denham.

4. An average. [R.] A medium of six years of war, and six years of peace. Burke.

5. A trade name for printing and writing paper of certain sizes. See Paper.

6. The liquid vehicle with which dry colors are ground and prepared for application. Circulating medium, a current medium of exchange, whether coin, bank notes, or government notes. -- Ethereal medium (Physics), the ether. -- Medium of exchange, that which is used for effecting an exchange of commodities -- money or current representatives of money.

Part of speech: adjective (a.)

Having a middle position or degree; mean; intermediate; medial; as, a horse of medium size; a decoction of medium strength.