(obsolete, dialectal, Scotland) But.
Current is the flow of electrons through a metallic circuit, with the direction of flow being from positive (+) pole to negative ( ) pole outside of the source (generator or battery). Direct current (DC) travels in one direction, only, while alternating current (AC) travels in both directions across the circuit. A continuous flow of AC current travels first in one direction and then reverses polarity and flows in the opposite direction. See also current, DC, and polarity.
A specification from Dolby Digital and the Advanced Television Systems Committee (ATSC) for audio compression.The audio sampling rate is 48 kHz, and the system supports six channels in the Dolby Digital surround format. That format specifies multiple channel outputs, including center, left and right center, left and right surround, and low-frequency enhancement (LFE), also known as subwoofer. AC-3 is specified by the ATSC for use in high definition television (HDTV) and standard definition television (SDTV). See also ATSC, audio, channel, compression, HDTV, and SDTV.
Origin of Ac
Fr -aque < L -acus < Gr -akos (or directly < any of these)
From Webster's New World College Dictionary, 5th Edition
New Latin -acus from Greek -akos
From American Heritage Dictionary of the English Language, 5th Edition