ad-

(From Latin: "to, toward, a direction toward, an addition to, near, at"; and changes to: "ac-, af-, ag-, al-, an-, ap-, aq-, ar-, as-, at-" and ad- is also combined with certain words that begin with the letters c, f, g, l, n, p, q, r, s, and t.)

The Latin element ad carries the idea of "in the direction of" and combines with many Latin words and roots to make common English words.