• @ sign

    symbol used in the formation of e-mail addresses (“@”)
  • A/D converter

    electronic component for converting analogue signals into digital signals
  • abacus

    mechanical counting aid for calculating the four basic arithmetic operations and extracting a root
  • abbreviation

    time- and/or space-saving textual short forms on coins, seals or in handwriting
  • abbreviator

    writer in the papal chancery who are expert in abbreviations and produce drafts of papal bulls and briefs
  • academic book

    book primarily specific to research and teaching
  • academic library

    library whose collection is primarily focused on academia and research
  • academic publishing house

    specialist publisher of academic books and journals
  • academy

    term for an art school or a learned society dating back to the time of the ancient Greek philosopher Plato
  • acidity (paper)

    an important consideration in papermaking because increased acidity levels (resulting from processes such as sizing) reduce durability