Merriam-Webster Collegiate Dictionary - an

 I. noun suffix  or -ian; also -ean  Etymology: ~ & -ian from Middle English ~, -ian, from Anglo-French & Latin; Anglo-French -ien, from Latin -ianus, from -i- + ~us, from ~us, adjective suffix; -ean from such words as Mediterranean, European  1. one that is of or relating to American Bostonian  2. one skilled in or specializing in phonetician  II. adjective suffix  or -ian; also -ean  1. of or belonging to American Floridian  2. characteristic of ; resembling Mozartean  III. noun suffix  Etymology: International Scientific Vocabulary ~, ~e, alteration of -ene, -ine, & -one  1. unsaturated organic compound furan  2. anhydride of a carbohydrate dextran AN  I. indefinite article  Etymology: Middle English, from Old English an one — more at one  Date: before 12th century a II  Usage: see a II  II. preposition  Date: before 12th century a III,2  Usage: see a II  III. conjunction  or ~'  Date: 12th century  1. ~d  2. archaic if  IV. abbreviation  Etymology: Latin ~num; ~nus year AN  abbreviation airman (Navy)