The acronyms for the electrical terms: Alternating Current and Direct Current. AC/DC adapters will convert AC current (typically household 120volts in the US) to typically a lower voltage in DC. An AC/DC adapter - converter will usually consist of a transformer, 2 or more diodes and often a capacitor. A famous band was named after this term, which was suggested by their sister Margaret after she read it on an electric sewing machine's label. The name of the band has strangely been interpreted as bisexual or Satanist at times.