e/Ground start

Information
has gloss	eng: In telephony, a ground start or GST is a method of signaling from a terminal or subscriber local loop to a telephone exchange, in which method a cable pair is temporarily grounded to request dial tone. Most middle 20th century American payphones used "coin first" ground start lines, with the starting ground passing through the coin itself.
lexicalization	eng: ground start
instance of	c/Telephony signals