medio-, medi-

(Latin: middle)

admedial, admedian (adjective) (not comparable)
In anatomy, toward or near the median plane: Greg read that the belly button of a person was located at the admedial position of an individual, this meant that the vertical symmetrical plane extended from the top of the head, through the navel, separating the right half from the left half of the body.l
ante meridian
antemeridian, antemeridiem (A.M.)
1. Of or belonging to the forenoon or "morning".
2. Before midday; applicable to the hours between midnight and the following noon.
anteromedial (adjective), more anteromedial, most anteromedial
In anatomy, pertaining to a location in front of and toward the middle line; anterointernal: In her book on medicine, Ines learned that anteromedial parts of the body were situated anteriorly and to the medial side.
1. In front and in the central line.
2. In medicine, situated anteriorly and toward the median plane.
aurea mediocritas
The golden mean.

Another meaning is "moderation in all things" which is interpreted as a willingness to live out one's days without taking great risks or without indulging in excesses. Horace, in his Odes, is said to mean, "Who loves the golden mean is safe from the poverty of a hovel and free from the envy of a palace."

An operation intended to center the pupil in the eye.
Making of an artificial pupil through the iris.
1. Divided into halves.
2. Having one part or side developed more than, or differently from, the other part or side.
The act of having a division into two equal parts.
graphic meridian, geodetic meridiageon (s) (noun); graphic meridians; geodetic meridiageons (pl)
A line on a spheroid or a reference ellipsoid (circular form): A graphic meridian links the points possessing the same astronomical latitude.
immediacy (s) (noun), immediacies (pl)
1. The quality or condition of being immediate: The immediacy of getting to the hospital on time is of great importance when a person is suffering from appendicidis.
2. Freedom from an intermediate or intervening agency; direct relation or connexion; directness: In the present time, it is so important to have the immediacy of live-television news coverage.
1. Occurring, accomplished, or taking effect without delay or lapse of time; done at once; instant.
2. That which directly touches or concerns a person or thing; having a direct bearing.

This word came from Middle English immediat, from Old French, from Late Latin immediatus. Etymologically, Latin in-, "not" and the past participle of mediare, "to be in the middle".

In 1392, imediat meant: "intervening, interposed"; later, in about 1410, it had the meaning of "absolute, conclusive"; then, probably before 1425, immediate took on the meaning of "nothing between, direct".

With reference to time, the meaning of "coming at once, done without delay", is found in 1558.

—Robert K. Barnhart, Ed.; The Barnhart Dictionary of Etymology
Without any delay or lapse of time; instantly, directly, no waiting; at once.
The quality or condition of being immediate; immediacy; directness (of action, thought, relation, etc.); absolute (or in loose use, relative) proximity in time or place.

A unit of medium, media words. The etymologicl development of media and medium.