acoustic delay line: a delay line based on the time of propagation of sound waves
delay line: a circuit designed to introduce a calculated delay into the transmission of a signal
church father: (Christianity) any of about 70 theologians in the period from the 2nd to the 7th century whose writing established and confirmed official church doctrine; in the Roman Catholic Church some were later declared saints and became Doctor of the Church; the best known Latin Church Fathers are Ambrose, Augustine, Gregory the Great, and Jerome; those who wrote in Greek include Athanasius, Basil, Gregory Nazianzen, and John Chrysostom