Definition of Lyle gun
1
: a mounted gun that resembles a small brass cannon and is used to fire a projectile attached to a line of rope to an extreme range of about 700 yards in rescue operations at sea
2
: a firing device that resembles a short shotgun and is used to propel a weight attached to a line of rope in rescue operations at sea or on land (as in firefighting) — called also
line-throwing gun
