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 L. ad 'to'.