Telecom is an abbreviation of telecommunication.
Colloquially it also refers to various telecommunications companies worldwide, among them state-owned national telecommunications monopolies, or companies derived from such monopolies after privatization. The term is now trademarked by various companies in their local jurisdiction, albeit always with a qualifier of locality (e.g. 'Deutsche' Telecom ), since 1985.
Telecom is also the name of a New York - based rock band active since 2004 in the United States.
Telecommunications companies using the term in their name:

Aliant Telecom, Canadian
Telecom Australia, a forebear of Telstra
Brasil Telecom, Brazilian
British Telecom
Deutsche Telekom, German
France Télécom
LG Telecom, South Korean
SK Telecom, South Korean
Telecom Finland, later Sonera, now part of TeliaSonera
Telecom Italia, Italian
Telkom Indonesia
Telekom Malaysia
Telecom New Zealand
Telkom (South Africa)
Portugal Telecom
Telecom Colombia
Telecom Argentina
Hutchison Telecoms, Australian
Telekom Srbija, Serbian
Telekom Srpske, Bosnia and Herzegovina
Maroc Telecom (also IAM), Moroccan
Pakistan Telecom
Bharat Sanchar Nigam Ltd., Indian