Source : WordNet®

telco
     n : a public utility that provides telephone service [syn: {telephone
         company}, {telephone service}, {phone company}, {phone
         service}]

Source : Free On-Line Dictionary of Computing

telco
     
         (from telephone company) A company
        providing phone services to end users.  The company may or may
        not provide other phone services such operating
        long-distance/international backbones but the name telco
        usually emphasises its operation as a local service provider.
     
        Compare: {PTT}.
     
        (1998-05-18)