dialler
noun [ C ]
(also dialer) uk/ˈdaɪələr/ us COMMUNICATIONS, INTERNET
a piece of software that allows people to connect to a phone number, for example over the internet, or by speaking a name or number into their mobile phone:
A web-based dialler is useful for computer users who do not have access to a traditional telephone line.
MARKETING, COMMUNICATIONS
an electronic device that calls a list of numbers automatically:
If a person answers, the dialer transfers the call to an agent.