a system that automatically connects a caller to a free line
preselector in American English
(ˌprisɪˈlektər)
noun
Radio
a preamplifier between the antenna and receiving circuit, used to improve reception
Word origin
[1925–30; preselect + -or2]This word is first recorded in the period 1925–30. Other words that entered Englishat around the same time include: Nazi, buildup, decibel, payload, recycle