AM

am (http://definr.com/am)

     adj : before noon [syn: ante meridiem]
     n 1: (Latin: before midday) the time interval from midnight to
          midday [syn: AM, A.M., a.m., ante meridiem]
     2: a radioactive transuranic metallic element; discovered by
        bombarding uranium with helium atoms [syn: americium, Am,
         atomic number 95]
     3: a master's degree in arts and sciences [syn: Master of Arts,
         MA, Artium Magister, AM]
     4: modulation of the amplitude of the (radio) carrier wave
        [syn: amplitude modulation, AM]