I. ˈlēˌdin noun
( plural lead-ins )
Etymology: from lead in, v.
: something that leads into something else: as
a. : the part of a radio antenna that runs from the larger or main elevated portion to the transmitting or receiving set
b. : something that opens or introduces : something that gradually leads the eye or attention from one thing to another
with a front-cover portrait serving as a lead-in to a five-page article — Publishers' Weekly
a lead-in which can attract people who don't agree with you — P.P.Van Riper
specifically : that part of a radio program or a radio broadcaster's talk which leads into the commercial
tuneful program lead-ins — Advertising Age
II. adjective
: that leads in — used especially of an electrical conductor
a lead-in wire
— see incandescent lamp illustration