ad-

ad- (also a- before sc, sp, st; ac- before c, k, q; af- before f; ag- before g; al- before l; an- before n; ap- before p; ar- before r; as- before s; at- before t) ► PREFIX 1) denoting motion or direction to: advance. 2) denoting reduction or change into: adulterate. 3) denoting addition or increase: adjunct.

ORIGIN from Latin ad 'to' .