Prefix
As a prefix ad- assumes the forms ac-, af-, ag-, al-, an-, ap-, ar-, as-, at-, assimilating the d with the first letter of the word to which ad- is prefixed. It remains unchanged before vowels, and before d, h, j, m, v. Examples: adduce, adhere, adjacent, admit, advent, accord, affect, aggregate, allude, annex, appear, etc. It becomes ac- before qu, as in acquiesce.
Source: Webster's dictionaryCurrently, the park improvement fund has $421,000, said City Ad- ministrator Mark Larson. Source: Internet
The BLM rule is part of a larger effort by the Obama Ad- ministration to curb methane emissions. Source: Internet
The term "adrenal" comes from ad- (Latin, "near") and renes (Latin, "kidney"). citation Similarly, "suprarenal", as termed by Jean Riolan the Younger in 1629, is derived from the Latin supra ( Latin "above" main) and renes ( Latin kidney main). Source: Internet
The Latin was itself a joining of ad- and gradi-, which meant step at. Source: Internet