auto-dialer

[ aw-toh-dahy-uh-ler, -dahy-ler ]
/ ˈɔ toʊˌdaɪ ə lər, -ˌdaɪ lər /

noun

a telephone device that makes possible a service feature (au·to-dial) whereby a call is automatically made in response to a brief input signal from the user, as the pressing of a button.
Also called automatic dialer.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019