Definition, synonyms and related words
Initialism of Asymmetric Digital Subscriber Line.
"The technician explained that ADSL is an initialism of Asymmetric Digital Subscriber Line used to provide high-speed internet access over telephone wires."
In plain English: ADSL is an older type of internet connection that uses your phone line to let you surf online at home.
"The technician came to fix my broken adsl connection so I could get online again."