Wiktionary
n. A company "that is engaged in the provision of telephone exchange service or exchange access" (except for wireless carriers, unless the FCC determines that the wireless carrier is to be included in the definition); that is, any '''local telephone company'''.
Wikipedia
Local Exchange Carrier (LEC) is a regulatory term in telecommunications for the local telephone company.
In the United States, wireline telephone companies are divided into two large categories: long distance ( interexchange carrier, or IXCs) and local (local exchange carrier, or LECs). This structure is a result of 1984 divestiture of then-regulated monopoly carrier American Telephone & Telegraph. Local telephone companies at the time of the divestiture are also known as Incumbent Local Exchange Carriers (ILEC).
The divestiture created local exchange carriers for the management of local telephone lines and switches, and provisioning of local phone services within their business area, as well as the long distance calls originating or terminating in their business area. The vast majority of the United States are served by LECs called Baby Bells, or RBOCs (Regional Bell Operating Companies). The rest of the United States, most commonly in rural or outlying suburban areas, are served by independent LECs, known in the industry simply as the "independents." Although independent companies typically serve these areas, RBOC LECs still have vast territories of low population density regions of the country. Therefore, independents generally exist as pockets of territory within a greater RBOC region. Popular independents are Frontier Communications, and Windstream Communications.
Local calls are defined as calls originating and terminating within a local access and transport area (LATA) which is defined by the Federal Communications Commission. All the Baby Bells, as well as other LECs, typically operate businesses in more than one LATA yet their services of local telephone calls are still defined by LATA boundaries, not their business areas.